You've got some good choices available, but I'll share what I am using in my office: a pair of Krix Equinoxes that I bought for $300 (used) on Audiogon. I think they're an excellent small speaker which meet your criteria for a true bookshelf unit. Some other choices might include the PSB Mini's, the Dahlias (Dick Olsher of Stereophile mag fame designed these), etc.
