I used Launcherpro plus for months and for the most part, I was very happy with it. It would freeze up sometimes when I would go to screen previews and the only way I could get out was to hit the home button again. Since it seems like the dev stopped updating it, I started looking at other launchers, and I've developed a bit of an addiction. I've currently tried launcherpro, pandahome, home++, zeam, powerstrip, go launcher, keeworld, and adw launcher, with several more on my list to try.
My favorite is go launcher. I don't have any of frozen screen effects that I had with launcherpro, and it has several options that launcherpro doesn't have. You can filter the app drawer by all, recent, or running. You can also choose the style of flipping between screens, such as "cube" or "windmill." It also has loop scrolling, so when you get to your last homescreen, it just flips around to the first one. Like Launcherpro, it has a scrollable dock with 15 dock stations, which you can either tap or swipe for a max of 30 shortcuts. You can add 30 homescreens or something ridiculous like that. The only thing I miss about launcherpro plus is the scrolling widgets, especially the contact widget. I've made up for that by installing animated widget.
I haven't really been able to test out adw launcher like i want to, because for some reason, I cannot change the number of homescreens. This seems to be limited to my phone, and is not a feature of the launcher in general. From what little I've seen of it, I like it, and I might even make it my primary launcher if I didn't have the homescreen issue. You can add up to 5 dock shortcuts, it's supersmooth, and from what I've read online, it is better on the battery than launcherpro.
pandahome 2 is also worth mentioning as a good launcher. it's pretty fast and smooth, although I didn't get quite as good a performance out of it as I did launcherpro, adw, and go launcher. One really cool feature is it has 6 dockbars, scrollable, that you can drag apps into. The only thing I didn't like about it is that you are stuck on a 4x4 screen; you can't adjust the number of rows and columns. It has up to 11 homescreens.
I used home++ for a little while, and it has a nifty "power strip," instead of a traditional dock. While it is scrollable, and pretty cool, it isn't customizable.