There's alot of great mods out there to check out. For what you're looking for though, you should check out The KOTOR and TSL Top Mod Picks by Year
. Thats pretty much where you're going to find the mods the community has released that are widely embraced and found to be the most desired. Also KOTOR Files
has the top mods downloaded section near the top that is a great resource for finding whats the most in demand for released mods.
Personally for TSL I recommend some of the restored content as it adds some flavor to the game. The Ultimate Saber Mod is nice to spice up the weaponry amongst other things, and M4-78 is an excellent addition to extend your playthrough. Besides all that, without just throwing a giant list of mods at ya, its hard to say whats good and bad for TSL. Those are the ones I'd say are excellent to acquire, but guess we'll see what the rest of the community says.