My 3 favorites at this day and time are:
#1 Wicked Sensations - Beautifully Themed - Very smooth, fast and stable. Very simple and easy. Flash, Load and Forget about it! There are no real issues with this one.
#2 Team Sonic FreeGS3 - Not themed out of the box but there are several for it. - This rom has everything but the kitchen sink - Use's the Aroma Installer, so there's many options to choose during installation - It started great but IMO it's getting a little bloated.
#3 JellyBomb Domination - Another Beautifully Themed Rom - Has a good assortment of mods but not overdone.