Getting from Budapest to Prague

I would use train to avoid hassle with flying. Add time going to and from the airports, time for check in, security etc. and flying is not that much faster then. Also there is an option to go by bus: www.orangeways.com

It is a long trip from Budapest to Prague. 7 hours or so. But if you take the earliest train possible, you will most likely sleep and be in Prague by 1pm or so. We had a railpass for 4 countries, Germany/Austria/Hungary/Czech Rep. We did not know we would be stopping in Slovakia. We were confronted with this by the ticket man who demanded payment (40 euro each maybe) for that installment of the trip. We had no money as we used up our Hungarian currency and planned on getting Czech money once we arrived in Prague. He refused our credit cards. All we had was 1000 Forints (which is like a buck or 2) and a 20 euro bill. The guy huffed and puffed, pocketed our money and told us to have a good day. We were scared and confused and lucky that we were not kicked off the train. So if you use a rail pass, make sure Slovakia is part of the deal.

We 2 were in Budapest and then Prague in October 2010. I debated the same issue, train vs. plane. We decided that flying was not worth the extra time getting to and from airport, checking in, security check, etc. Then we debated train day trip vs. overnight. We finally settled on a morning train. It was so fantastic; we saw the countryside in Hungary and Slovakia. There is something wonderful about approaching a city never visited before by train. We splurged for 1st class and the train was one of the highlights of our trip to Hungary and the Czech Republic. We shared our compartment with 2 couples who we did not know prior to the trip. They were lovely, friendly, interesting... We decided on lunch together in the dining car. The food was regional and very good. Our new friends and food, wine and beer made for a travel experience that confirms why we travel. In short, the train is more than worth it.
I hope you have as wonderful a trip as we had visiting Hungary and the Czech Republic.

If you have the time, take the train and stop for a couple of days in Vienna! It is a beautiful city with lots to see and do. I took the train last May Budepest - Vienna - Prague. The train is very modern and comfortable, the train stations are right in the city, and the cities have trams and subways. Getting to/from the airport is either by shuttle (extra time) or by taxi (extra time and money), so even without a stop in Vienna, it is probably easier to take the train than the plane. I chose the train over the bus, so I could travel in the evenings and use the daytime for sightseeing.