one's i've used personally:basic kit ($50 and below)
Used this crummy little Radioshack unit
for a good while.
it's fine for light work, but constantly heating things up and etc, look elsewhere. takes it a while to stabilize temperature back after making a joint. and no other tip sizes (which you have to special order) sucks. but if you're doing light work it's not bad and it's cheap.
a step up from that would be a Weller WLC100
. Used it a coworker's place and for light HAM work he finds it a good workhorse.
heats up quick and has a decent temperature range. non-grounded pencil but the base accepts grounded ones. Again good for light work, good range of tips, and fairly cheap.Dedicated Soldering Stations (typically $100+)
is a great unit, but expensive. I've only used this one at a friend's workstation and it's a great tool. tips for it are everywhere (I found the stock tip to be rather unwieldy on SMT stuff but that's just me it seems), but a bit pricy however.
The Hakko 936-12
is the unit i personally own and currently use. Stock tip is good for SMT stuff and it's base unit is smaller than the WES51. another plus is that i got it for $80 shipped off ebay. watch for the model differences though, if i remember correctly: -11 is small (tiny little pencil), -12 is medium (good for most anything), and -13 is the heavy duty one (big, honking tip)
just the ones i've played with. hope it helps