Depends so much on what type of listener you are, how much you get involved in the music, how much passion you like, emotion and depth, nuance, precision, fun, all those things and much more. I've always found Mozart to encompass most of the things I like along those lines, especially the in the 40/41 symphonies. And Bohm is a very good interpreter. But I also really like some of the Neville Marriner recordings too. In any case, buy used and you can buy a lot for very cheap. Check out the Bohm 41 on youtube in 4 parts ... part 1 is at http://www.youtube.com/watch?v=noAPeUlOjfc
(and one of the comments also mentions Marriner - good advice).