The HTC Vivid, one of AT&T's mid-range (if you can call it that) phones is getting an unofficial bump to ICS courtesy of, who else? XDA. User Pirateghost has offered up a flashable Android 4.0.3 ROM. Stock, rooted and ready to go. It even comes with all that AT&T carrier bloat intact. You're getting the 100% pure, unadulterated stock experience with this one, just rooted.
As you can see, while it reads like ICS, it hardly looks like it at all.