I like the Salarians, which is odd to me because my robo-philia should pretty much guarantee that I like the Geth (or by extension the Quarians)... but there's just something about the physically-frail but almost nefariously intelligent Salarians. Mordin is probably my favorite character in the whole series (which is, believe me, not an easy distinction to make... most of the ME2 cast is VERY good). I also like that, unlike the other major races in the ME universe, the Salarians have shorter lifespans than humans. I don't really know why I like that, but I do.
I'm sad that the Salarian Infiltrator in ME3 Multiplayer isn't very good, and I don't have the Engineer. I wish I did.