In no particular order because there isn`t one pre that does it all and I have not had the pleasure of hearing every pre thats ever existed but these are the ones I really love from what I have used or heard.... Avalon 737
: I agree with etrella that its overpriced, but the pre does the job for most apps, its built like a tank, the EQ rocks and the DI is great on bass.
Martech MSS-10: probably the most open sounding pre I have ever heard on vocals and guitars
A Designs Pacifica: just has that smoothy silky sound to it... ahhh... most likely a 2010 purchase!!! Manley Voxbox
: warm, round, "in yer face" but not harsh, also overpriced.
Grace 101: the best pre in the $550 range, surprisingly open sound and balanced, especially on baritone vocals and acoustic guitar