So far I've flashed four different ROMs to my Captivate. The first was Serendipity 6.4, froyo. Great ROM, but soon after I found it Serendipity VII was released - Gingerbread : ) S7 is extremely stable with great performance. I recommend it to anyone who wants a great ROM that simply works. It also comes with some great themes.
Next up is DlevROM 4.2. This ROM is very snappy and features some cool animations. The screens would flip, turn, and twist with every change. The theme was nice for this one as well. I experienced some lock ups with this ROM, but nothing too severe. Probably something I did, so don't blame the ROM. Version 5.0 has been released, but have yet to have tried it. Development seems to have stopped on this one, as Dlev's cappy has recently suffered an unfortunate accident. He has since moved on to the SGS2.
As of now I've settled with Mosaic VI. This is another extremely stable ROM with great speed. It comes with a great orange colored theme and many more can be found here and here. There is even an OTA app and website, which is quite nice.
I'm using the Firefly theme.
So that is the run down of the ROMs that I have used so far, but I'm sure it won't be long before I change again. I'll pass it along when I do.
If your looking for wallpapers and icons to make your android even more unique, head on over to Mortem Taum's site and check out his latest creations. He does some awesome work.
Here is my latest. I'm using GOLauncher and ClockQ.
So what's on your phone?