I agree, TAC Vader is probably my favorite. Mainly for the fact that he doesn't have the silver thread and he can hold his sabre with two hands in a duel with old Ben.
I like the head joint on the VOTC though, it's quite good for scowling down at other characters, or up at an escaping Millenium Falcon. I didn't even realize the figure had this feature until I got a duplicate with an imperial shuttle years later, and moved the neck by accident.
I didn't know the head on that Vader moved up and down! I never tried it!
Until then...I guess the 30AC version is my go-to, even though I only bought it at the time for the Ben Kenobi robe accessory.
I bought that figure for the same reason (I figured it was the only Ben Kenobi figure I didn't have), but the Vader figure made the perfect pilot for a Sith Starfighter pilot.