Budapest and then 3-4 days in ... ???

Are Paris and Brussels your choice of departure cities for flights home?

I don’t think 3-4 days is enough for Paris.

Day #
1. Train (6.5 hours) from Budapest to Prague (3N)
2.3. Prague
4. Early flight from Prague to Brussels (1N)
5. Home to USA

I haven't been to Prague for 45 years, so I'm not speaking from experience here, but I'm under the impression from comments on this forum and elsewhere that the historic highlights in Prague (Castle, Wenceslas Sq, Charles Bridge, etc.) are extraordinarily touristy, so I'm not sure that's the best choice for someone who doesn't want to fight crowds. Which is a shame, because 4 days is probably a very good amount of time for a visit to Prague.

The central historic area of Ljubljana (along the river) was packed with visitors when I was there during the summer of 2015, though not to the degree that it pushed me over the edge. Outside that core, there were no foreigners. Still, I don't think it's what you're looking for.

Zagreb is a much larger city but less touristy. If you enjoy art museums you could certainly fill your time there easily. If not, 3 or 4 days might be too long, though the bi-level historic district is very attractive.

I believe Belgrade is still rather lightly visited in general, though I think it has something of a party-town reputation. In 2015 it had a distinctly different feel from the other places I went in the Balkans. A side-trip to the interesting town of Novi Sad would be possible. You will definitely know you're in a different country if you go to Belgrade.

Can't comment on Sarajevo--too short a visit and too long ago.

Lyon's great, and 4 days would be good there. It's not an undiscovered destination, however.

I wish I could compare these places to Budapest, but that's another 45-years-ago place for me.

Are you flying home from Budapest or can you choose another departure city? If Budapest, have you considered Vienna for your second destination? About 2.5 hours away by train, lots to see and do. If you can fly home from elsewhere, then Paris or Lyon (which probably means flying home via Paris). The 3-4 days you have would be enough for Lyon or Vienna (or probably your Balkan candidates though I haven't been). Not enough for a really satisfying Paris visit, but enough to make you want to return to, as some call it, the Budapest of the West.

Prague is wonderful but very crowded.

Belgrade is fascinating and not too big so a short trip there would work, ditto for Sarajevo which is my favorite city in the Balkans. It's stunningly beautiful.

If you like wine and museums, Vienna seems like the obvious choice even if you didn't list it here. Austrian wine is wonderful and there are so many good wine bars in Vienna.

Hi, all! Thanks for the responses so far! Very helpful!

Sorry if my list wasn't clear. The first five options I'd bus/train over ... I don't have a particular preference as to where I'd start my return flight to the U.S.

I've been to Vienna but only for 3 days. I did Schonbrunn and a bus around the city, but that's it. If you think I missed any must-dos there, I'm not against that idea of returning -- although I'd prefer someplace new.

In case it comes up, I've also been to Munich many times. :)

Based on this info, I'd really recommend Sarajevo. It hits all the boxes except wine. Wine is produced in Bosnia and there is a wine bar in Sarajevo, but you're not going to get the variety of wine, let alone commonly encounter it in restaurants, in the same way you would, in say, Zagreb (which might also be a good outing for you, I just haven't been there so I can't personally recommend it . I know Croatian wines are starting to become well known and better regarded internationally, though)

Here's a link on hiking: https://www.balkanvibe.com/story/5-Fall-Hikes-Around-Sarajevo/226

Depending on your tolerance (or not) for awkward or costly flight routings, I'd suggest checking how you would fly home from the various places you are considering before making a final decision. If you live in the NY metro area, it may not be an issue, but I'm not sure.

My first thought was also Vienna, given that it's so close to Budapest (less than three hours direct on the train). If you enjoy museums, there's plenty there to keep you busy. My favorites are the Kunsthistorisches (world-class art), Haus der Musik (lots of interactive exhibits, including a chance to "direct" the Viennese Philharmonic) and the Hofburg New Palace Museum (your mileage may vary here; I enjoyed seeing, say, three 18th Century oboes, but recognize others might not). Since you've seen Schönbrunn, you might enjoy the Hofburg in the city. It focuses on the 19th Century, specifically Franz Joseph and Sisi.

However, if you're looking more to relax - how about heading to the Wachau Valley? I stayed a few nights in Melk and did the bike ride to Krems. It's lovely and very laid-back. The Melk Abbey is beautiful, and, while I didn't get a chance to do this, you could probably get to some wineries. I did just a very quick google search and there are tours (although most seem to leave from Vienna). Melk is less than four hours from Budapest (one transfer), or you could go Budapest-Vienna-Melk; trains from Vienna are pretty frequent.

NOTE: I lied. My first, knee-jerk reaction to your question was, "Lake Bled!" Lake Bled is one of the most beautiful places I've ever seen. If you're looking for quiet, this is your place. When I visited it was early June, and not crowded at all. Unfortunately, it's at least 8 hours (or more) from Budapest. It is, though, only an hour from Ljubljana, which I haven't had the chance to visit but have heard from friends that it's wonderful. If you're willing to go that far, an extra hour to Lake Bled might be worth it. The only drawback is getting to a major airport to get home might be an issue.

This really depends on your taste. For me:

Prague: A Disneyland utopia with overly restored, but stunning, medieval architecture and wall to wall tourists all gawking at the same clock.
Belgrade: Great young party town with maybe two days of historical context and sights to see. But i did enjoy it.
Sarajevo: Not impressed with what i have read. But on my radar for some day.
Ljubljana: Too hard to get to (too long actually) from Budapest
Zagreb: See Ljubljana above.
Flyover to Paris or Lyon (never been to France): I love Paris! But i would stick to Central / Eastern Europe
Flyover to Brussels (never been): Just didnt light my fire.

Okay, now that i butchered your list. Here are my favorites, but first, its going to be about the day of the week because there are all short discount fare flights (mostly under $90 and 1.5 hours):

A lot of names here. What i do for starters is just put the name in Google Images and see if i like what pops up. If yes, then i begin the research.

Titograd (Podgorica). Not so much for the city, but because its a short trip to Budva and the coast. Its also a short drive to the mountains if you are into nature, fishing, old monastery built into the side of cliff, etc. I love Montenegro. Two trips so far and a third soon. I know a young lady that is an excellent guide. Wizzair is under $100 on Tuesday and Thursday and Saturday

Kyiv: Oh my g-d! Into the throat of WAR! Naaa, Ukraine is roughly the size of Texas. The Russian incursion is in Corpus Christi and Kyiv is in Abilene. To be interested in this you really have to interested in modern politics and social culture. Well, not entirely as there is good architecture, some catacombs, etc. It would be like no trip you ever took before. Again, this is a place i adore. We head back in a few weeks. And I know a guide here as well. With four days you could spend two in Kyiv and two in Odesa or Lviv. Flights to/from Kyiv run daily.

Sofia: Another place i keep returning to. Okay, i am one of the few that really like Sofia, but no one can argue that its not worth a day or two. The real charm is outside of Sofia though. You will need a guide (I know a great woman). The trip would include (other than Sofia), the stunning Rila Monastery which i suspect is like nothing you have ever seen before and if you love history the Bachkovo Monastery which protected the Jews during the Holocaust. Then on to what i think is one of the best kept secrets in Eastern Europe: Plovdiv. From ancient Roman theaters and floor mosaics to excellent examples of ottoman architecture and every style since. Good food, good people. Just a dang nice place to spend a couple of days.

Wizzair is under $100 on Tuesday and Thursday and Saturday

Of course, you could also spend those days in Hungary! Each of these is 1.5 to 3 hour train ride

Tihany on Lake Balaton: Wonderful little artist town on the banks of the lake, complete with Abbey on ancient foundations. https://www.google.com/search?safe=off&rlz=1C1GKLB_enUS644US646&biw=1536&bih=735&tbm=isch&sa=1&ei=MCrOWtflBaSijwT-m7zoDA&q=tihany+hungary+tourism&oq=tihany+hungary+tourism&gs_l=psy-ab.3...26251.27581.0.28112.7.7.0.0.0.0.63.389.7.7.0....0...1c.1.64.psy-ab..0.3.173...0i13k1j0i13i5i30k1j0i8i13i30k1.0.vZEXwSXBmOU

Eger in the wine regions: https://www.google.com/search?safe=off&rlz=1C2GKLB_enUS644US761&biw=1536&bih=735&tbm=isch&sa=1&ei=hyjOWo6tOuPujwTVxJHQAg&q=eger+hungary&oq=eger+hungary&gs_l=psy-ab.3..0l5j0i30k1j0i24k1l4.337774.339710.0.340060.12.10.0.2.2.0.98.534.10.10.0....0...1c.1.64.psy-ab..0.12.552...0i67k1j0i8i30k1.0.wHKEFAGqflc

Pecs where the ottoman influence still stands: Wonderful city in a warmer climate: https://www.google.com/search?q=pecs+hungary+tourism&safe=off&rlz=1C1GKLB_enUS644US646&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjUve2XxbLaAhUM6YMKHWszCOwQ_AUICigB&biw=1536&bih=735

Gyor and the Archabbey at Pannonhalma: I love the archabbey and the old city center is fascinating, beautiful and full of good food.
Gyor: https://www.google.com/search?q=gyor+tourism&safe=off&rlz=1C1GKLB_enUS644US646&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjQ0_PaxbLaAhUi8IMKHWfxBNUQ_AUICigB&biw=1536&bih=735

Archabbey: https://www.google.com/search?safe=off&rlz=1C1GKLB_enUS644US646&biw=1536&bih=735&tbm=isch&sa=1&ei=uyrOWuSKJKOLjwSBn4ZA&q=pannonhalma+tourism&oq=pannonhalma+tourism&gs_l=psy-ab.3...43868.46830.0.47398.11.11.0.0.0.0.121.648.10j1.11.0....0...1c.1.64.psy-ab..0.6.411...0j0i13k1j0i7i30k1j0i7i10i30k1j0i8i13i30k1.0.HFopiX-Dkhg