I tried an electric nailer.
It sucked.
I'd go pneumatic.
I'd get a cheap and "quiet" compressor like the Husky Air Scout ($89) or (if you have the $$) the Makita MAC700 ($170). You'll find lots of uses for a compressor, so don't be afraid of one. A 1 or 2gal compressor takes seconds to fill and are not that unwieldy to use. You'll find many uses for a quality compressor.
Then you can get any array of brad or finish nailers. I've had good experience with Porter Cable, Bostich, and Dewalt.
Kobalt (through Low---es) sells a regulator ($100) and CO2 cartridges ($10/ea) that can replace your compressor. Nice for quick jobs. Honestly, my Husky is maneuverable and quiet enough that I don't mind whipping it out even for a 30min job.
If you have Dewalt 18v tools, you could get a refurbed cordless finish nailer from Tyler/Toolking/eb--ay and use yr current batts. I don't think they make a brad nailer, though, just 16/15ga nailers. Am I wrong? This is the only cordless nailer that I read a lot of good press about. However, with everything going Lithium Ion, unless yr reasonably certain Dewalt'll make new batteries backward compatible w/ it's tools, I wouldn't invest in this unless I had other 18v NiMh's that this thing could share with.