Wow this is about as vague as it gets actually but I'll do my best to explain a few of the most popular ones since I'm a dsm guy.
EvoIII 16G is one of the most popular turbo's on the market, quick spooling (usually around 3400ish) makes it great for the street, a great 12 sec (even 11's and in one or two cases 10's) turbo its definately a fun little upgrade, flows a little more then the Big16G or the small16G which are both great turbo's in their own right, these normally do not require forged internals
50 Trims, about a year ago this was all the rage, 50 trims are easy 11 second turbos with the right supporting mods, the FPGreen is a 50 trim turbo and in my opinion is the best one out there. Still very streetable and a whole lot of fun. Time to upgrade your internals though and cams
60-1 turbo's are starting to get out of the streetable range although many will debate they are still good for the street, once boost kicks in though hold on tight because this baby will move your machine. Definately look into internals and a good set of cams
FP 3052, right now one of my favorite turbo's, not a whole lot of them out there due to the cost but its one of the best street turbo's I've witnessed, Being ball bearing makes spool up a cinch, on pump gas there have been 500+ plus hp machines made, obviously internals and supporting mods are a must.
FP3065 and 3575 for a full review on these two check here: http://dsmtuners.com/forums/showthread.php?t=203475
From there you can look into T3/T4 options for more go the Gt35r is very similir to the FP3065 in characteristics only in a Garrett housing, from there the GT42R is the mother of 4G63T turbos capable of 7's (as of currently although there are rumors of Shep possibly stepping up larger in the future)
Other options that are no longer as popular but are still great turbo's include
20G's, this was the first turbo to power dsms into the 10's and is still looked upon as a great turbo by most knowledgeable dsmers, although it has been replaced mostly by the 50trims as a turbo that is cheaper and performs similarily.
18g not very popular at all but loved by most who have run one.
T28, if your running a second gen dsm setup this will bolt right up although I would bet most swaps on here are the loveable first gen 6 bolt setups.