How bout Myriad Pro. A nice solid humanist sans, that tracks well in paragraphs. Plus it won't look cold and lifeless like Helvetica does.

failing that, one of myriad's ancestors, frutiger

oh, and the pedant in me has to say that it is 'complement', not 'compliment'

Maple
Bureau Grotesque
Dyna Grotesk

Anything Grotesque

Héctor

...or Gothic, for that matter: Franklin, Trade, News, Alternate, Titling, Nick Shinn's Brown Gothic, etc.

Other grotesques to consider:

Super Grotesk
FF Bau

I third the grotesque comment -- try Monotype Groteque or Gothic 720 (Bitstream version).