I have many favorites, but I will just list a few.
Android Assistant: I started using this before I ever rooted. Besides being.a great app saver it moves to sd, does batch install & uninstall, cleans cache, cleans up your browser history, search history, it has a task killer.....18 tools in one.
Beautiful widgets: when I had to downgrade my evo to this metropcs phone, I really missed my animated weather clock on my home screen. That's what I was used to, I had the htc hero before that. So I searched until I found something comparable. I like that I can change my clock & weather skins. It also has a battery widget.
Handcentsms: I have used this since the beginning of my android days & love it.
Screenshot UX: I tried several trial version screenshot apps before buying this one. I just really like it. You can choose which file to save the pics in. You can crop, edit draw stencil, it's just a good app.
ROM Toolbox: must be rooted as with the screenshoot app as well. This app has ROM manager in it (although that isn't compatible with my phone & will brick it) oh sorry, I have the PRO version. Other features include; apps manager, file browser, DNS changer, ad blocker, rebooter, cpu control, build prop tweaks/editor, terminal emulator, configure your memory allotment, change the speed your sd card writes, font installer, icons & I don't remember how many, but several bootanimations.
Lastly, I tried several twitter apps before finally settling on Twidroyd Pro . Not a lot to say, it's twitter, lol just personal preference.
Anna