This ought to get a lot of replies. Seems everyone has a favorite launcher. I have been using Solo with very good results. I like the gestures, they are easily configured and useful.
Beyond that, I haven't seen that much difference between launchers. The biggest change I have seen on my phone was installing Organized Drawer, which gives me a different app drawer that I can organize easily with folders. I have over 100 apps on my phone, organized into 13 folders, with 3 apps not in folders. All on one page, and everything easy to find. It's a nice app if you want to get stuff organized.
LG Optimus V - ICS, now retired as an alarm clock
ATT HTC Vivid - S-Off, rooted, unlocked, Dirty Unicorn