Every day at work I put an average of 2500 nails through this Hitachi NT65A3 Finish Nailer, 16-Gauge:
http://www.hitachipowertools.com/store_item.php?iID=159&arrPath=1,9,44,p159,
We beat these things up pretty bad, we've got 7 of them, 5 Paslodes, and a bunch of other miscellaneous brands. We all prefer these for the bazillion feet of trim that we do. They've survived falls off scaffolds, total submersion, poor maintenance practices [:I], and I've only seen one have to go to the repair shop for a broken spring. They are real workhorses. We use them for everything, hanging doors, all types of trim, oak handrails and balusters, custom built-ins, you name it, we've nailed it.
They never jam unless you try to drive a nail into something like a steel beam or the head of a drywall screw, and fixing the jams is very simple and tool free. We use 2" galvanized nails for everything, unless we need a little extra stretch to bite into something a little farther away (stupid framers work in 1/2" precision), we'll load up the 2 1/2". It'll hold 150 nails, so we're not constantly having to reload them as much. The nails are cheap, and they leave a nice small hole, too.
Here's my baby, she's not as pretty as the one in the above link, but it still works like new:
Here at the house I have a Porter Cable 15 gauge angled nailer, but the cost of the nails is so high that I rarely use it.
Hope this helps!