Ricky (Senior Airfare Analyst): Boston to Budapest $726 round-trip on Lufthansa/United. Travel is valid through June 11.
Where to Sleep: If you've got money to splurge, the Four Seasons Gresham Palace is consistently rated amongst the top hotels in Europe. Otherwise, you can easily find reasonable apartment stays. I prefer the Buda side, since its a little more low key and quiet compared to the Pest side across the river.
Where to Eat: Menza located near the Oktogon Metro stop has delicious traditional Hungarian food, such as goulash and beef stew.
Have a Drink: Szimpla Kert is the most popular of Budapest's ruin pubs and one of my favorites to just lounge and people watch, another is Corvinteto located on a rooftop near Blaha Lujza ter, which often features DJ's and other live music.
Favorite Things to Do: If you are there during August you have to go to Sziget which is a week long music festival that takes place on an island in the middle of the Danube. You must also try out one of the spa's and hot baths (furdo) that popularized Budapest. Szechenyi being my favorite due to its size and outdoor space, but Gellert is also an Art Nouveu masterpiece worth checking out as well.
What to Buy: I always grab some some paprika and Zwack which is an herb liqueur to take home. Egészségedre! (Cheers!)