I haven't even played tenkaichi yet, so i'd have to say esf. I get a lot of good compeditive fights out there, and given the fact that I really didn't like the other budokai games and that I hardly play console games anymore, I'd have to say esf purely because I know I can always get a good fight.
ESF has more variation but Tenkaichi has a much better control system. ESF's melee system is very basic whereas Tenkaichi's is deeper however Tenkiachi's melee gets annoying and repetitive after a while.
I'd probably say ESF overall because Tenkaichi annoys me in places. If ESF tightened up its controls it would be an easy win.
I prefer ESF's, but ultimately it comes down to basic melee (swoop punch swoop punch) and advanced melee (arrows... -_-), teleport, throwing (*cough*) and blocking. It is my oppinion that although it lacks the depth of Tenkaichi, it is faster paced and more exciting.
Tenkaichi allows you to swoop, teleport, block, counter or use a close-range ki attack to shatter blocks. You can sidestep or backstep attacks too and charge your punches. It basically takes advanced melee and replaces the arrows with an actual combat system. You can still do the BT equivalent of basic melee with decent speeds and knockback.
I would say Budokai Tenkaichi is just a little bit better than esf only because of the characters and being able to destroy the arena but in esf i can easily play around and not get attacked and dont main have to use beams to win
ESF over Tenkaichi. Maps in Tenkaichi were way too small, the control isn't nearly as fluid, and the fighting system is weak. I've played ESF for almost a year, and I still pick it up from time to time, where I stopped playing Tenkaichi after one day.