Wasting few bytes and cpu cycles, but I will agree with rest of crowd:
1) Modded Pioneers by Dennis (AAs)
2) Athena - I haven't heard them myself, but before Klipsch destroyed them, they there, at-least by reputation, very good budget speakers.
3) 100% agree with Mark on budget Polks. - Few years ago I went to stereo dealer in Miami and heard every single Polk bookshelf they had in stock - about 8 of them.
They were all crap, except last one - LSi/7 - but they cost arm and a leg. Long story short - stay away from budget Polk and on top end of the buck - there better choices at price point of LSi (currently LSiM)
a bit about myself - I am no musician, but I did had few years of training in music school and I do hear quite easily if someone misses a note
Another Brand to consider (actually two) is Ascend Audio and their new sub - Wave Crest audio.
Both produce very musical speakers on very affordable prices.
I also recommend to stick with bookshelves and sub, rather than towers. Unless you have very large room and need the extra volume