Places similar to Hallstatt but easier to reach from Munich?

You may enjoy Innsbruck, Austria or Salzburg which can be reached by train from Munich, though staying overnight would be preferable.

I'm curious exactly how much time you have. You said you will be based in Munich for a few days but already have plans to visit Rothenburg, Nuremberg, Regensburg and Neuschwanstein. That in itself would take 1 whole day for each town, plus 2+ days in Munich to see it all. So that's 6 days right there. How much additional time do you have?

That said, I would concur with the above recommendations, but would probably prefer Salzburg. It's a bit closer (1 hr 45 min) by train and it is beautiful with so much to see and do. However, I also agree that it would be much better to spend the night there if possible.

I have not been there, but have heard good things about the Chiemsee area. There are two lake areas just southwest of Munich of which I know someone on the forum has made recommendations for a laketown before. And then there is Berchtesgaden with the nearby Königsee.

Thanks everyone.

I'm flying into Nuremberg and will have 4 hours to explore (I've download a walking tour from bigboytours). I'm then travelling to Rotenburg where I'll stay overnight and do the Night Watchman tour. The next day I have a few hours (I'm an early riser) to explore and then I'm getting a train to Regensburg. Have 3 hours there until just after dusk and then headed to Munich. I've been to Munich before so using it as a base and have some days free there. I have two days for day trips, 1 to Neuschwanstien (will take the early train and will be back in Munich by 3pm) and 1 day think I'll take your advice and head to Saltzberg. I love to walk cities and I'm not one to necessarily go on a tour of a gallery or castle, I prefer the outdoors and the facades.

If you want truly beautiful Alpine scenery, as you originally indicated... there's no dreamier town than Mittenwald.

https://www.butterandfly.net/wp-content/uploads/Mittenwald-Germany-14.jpg

Direct morning trains from Munich's central station get you there in 1 hr. 40 minutes.

Here is a guide for walking the town and getting to the scenic spots and points of interest:

https://hastingshouse.typepad.com/hastings_house_us/2007/04/mittenwald_germ.html

You should not expect to find "...fairytale-esque Bavaria" in Nuremberg and Regensburg. Both of these make for very worthwhile visits on many grounds, but they are quite different from the Disneyesque, amusement-park-like destinations of Rothenburg and Neuschwanstein.

Just go to Innsbruck by train form Munich. Spread out from there.

It isn't as spectacular as Hallstatt, but Königssee, in Berchtesgaden is a beautiful lake, similar to Hallstättersee with the steep rock sides. If it's a similar lake you are looking for, Chiemsee doesn't have steep sides and Mittenwald doesn't have a lake.

With the time you have, go to Chiemsee. It's an easy, quick, train ride from Munich and quite beautiful.

I am with Lee on this one - the Koenigsee is amazing. Do the 20 min or so hike to the Ubersee if the boats are still running. It is the most beautiful place I have ever seen.

My second choice would be Oberammergau - the art work on the buildings is amazing. I think it is also worth stopping at the monestary in Ettal as well. Oh and the Wieskirche. These places aren't terribly far from Neuschwanstein.

I’d agree with Mittenwald. A postcard Bavarian village with an alpine backdrop come to life.

Mittenwald would be good and you can hike up to a couple of close by lakes, or take the loop trail for about 4 hours at the local gorge. The town itself is super amazing picturesque and the train station is near the town center and has a great cafe as well.
https://www.thefearlessforeigner.com/destinations/europe/austria/leutaschklamm-gorge-hike-mittenwald-germany/

Salzburg is wonderful as well and is great to walk around. It's a little ways from the main train station to the old town but it's a flat walk but not pretty at all. Once you hit the river the views are awesome and you can stop at a cafe and have a refreshment and look across the river at the old town and castle above. You can take the funicular up to the castle from the back of the old town area, and then walk the trail through the forest up on the bluff before heading down via the Augstiener brewery and back into town along the river.

A day trip to Herrsching and walk up to the hilltop Andechs brewery is nice as well. You can also go to the Ammersee after. https://www.munich.travel/en/pois/lakes-mountains/kloster-andechs

Strobl, St. Gilgen, and St. Wolfgang near Salzburg are on the lake (Wolfgangsee) and very pretty towns. But realistically, Salzburg is the better destination without a car. But I think you can get to St. Gilgen by bus from Salzburg. You'd have to check. Same for Mondsee.

In 2011, I went to Mondsee by bus from the Salzburg Hbf, then on to Hallstatt via St. Gilgen (no change, just went through, but the bus did stop) and Bad Ischl. So yes, you can do it.

In 2011, I spent a night in Mittenwald, then it 2013, on my way from Pfronten to Oberammergau, we went through Garmisch-Partenkirchen, so we made a side trip to Mittenwald for lunch. It's a cute town, but no comparison to Hallstatt.

Hallstatt, with the town hanging on the side of a steep sided glacial lake, is extraordinary. I don't think anything can compare with it.

I like Köngssee, for its steep sided lake, but it does lacks the picturesque town, like Hallstatt.

One place not yet mentioned is Oberstdorf, in the Oberallgäu. Oberstdorf is a cute town that naturally looks like Vail would like to be. But the best part is that it is a short bus ride up into the Kleinwalsertal, a high valley that is on the German side of the ridge to the Tirol, but part of Austria because the Walsers, who live there, were Austrian subjects. Kleinwalsertal is one of the most beautiful parts of the Alps I've ever been in, and easy to get to from Munich.

Oberstdorf is only about 2½ hours by train from Munich.

... Neuschwanstein castle so have the fairytale-esque Bavaria covered.
I want to however visit the Alps, and ideally would go to Hallstatt in
Austria.

To be clear, when you visit Neuschwanstein Castle, you also reach the edge of the Alps. You can take the Tegelberg cable car up the mountain or go for a walk along the Alpsee, just behind Hohenschwangau Castle.
https://en.schwangau.de/sightseeing/the-tegelberg-cable-car-and-summer-luge
https://www.seen.de/alpsee-hohenschwangau/fotos/

You have already received many good suggestions. Here are two additional typical day trips from Munich to lakes in the Alps.

Tegernsee, easily reached by train from Munich in just over an hour. Very beautiful landscape, lots of easy hikes or a boat trip on the lake. Well, the mountains are not as high and steep as in Hallstatt.
https://www.tegernsee.com/en/tegernsee-town

Walchensee, by train to Kochel and then by bus 9608 to Walchensee takes 1 hour 40 minutes.
https://www.seen.de/walchensee/fotos/
Here you can also enjoy the shore or take the Herzogstand cable car up the mountain for an incredible view.

Both are very popular destinations from Munich, so it's best to avoid the weekends.

I will second Walchensee. It's a very scenic area, but I'm not sure about places to stay.

I first saw Walchensee in 2009, while traveling from Bayrischzell to Mittenwald. I was so impressed that I made sure to do the Garmisch-Partenkirchen to Kochelsee route again in 2013 when I went from Oberammergau to Bayrischzell. Both trips were by bus.

Salzburg would be my preference. Buy a one day Salzburg card and take the regional train or OBB to the city. Get off and take the bus into town. Walk by the river, take the lift to the fortress and get some great views. Easy day trip.