Although the T-Mobile Vibrant, a derivative of the popular Samsung Galaxy S, is an aging phone, it has recently received an important spark of life. Ever since the source code for Android 4.0 Ice Cream Sandwich dropped, the developers over at XDA have been working on getting a quality ROM containing Ice Cream Sandwich Working. I have been following the series of ROMs called Passion which were among the first to launch.
Passion recently launched Beta 12. Don't let the moniker "beta" fool you, this ROM is definitely good enough for a daily driver, and has been since at least version 6. All of the expected features work, internet, phone, sound, video, playback, camera, etc. It's much faster than the phone ever was with prior versions of Android, and looks great.
The only missing feature, which is due to a lack of hardware, is face unlock. It would be very nice to be able to see this feature live, but without a front-facing camera, this will never be available. Theoretically, they could make face unlock work with the rear camera, but I doubt they will spend the effort to do so.