ChronoTrigger

First of all, I am not very good, so I like turn-based.
But the turn-based had strategy associated with it because it was really timer-based. Your next turn varied depending upon your cast and what attack method you used. Also, there was the ability to use combo moves -- which meant trying to line-up everyone's timer.
Finally, three words -- NO RANDOM BATTLES. I had trouble with many an FF game because of that.

Mike from Morgantown

The Grandia battle system is mad secksy. I'm surprised it hasn't been mentioned more often.

FF9,standard and good enough to adjust to the game quickly

unlimited saga battle system was hard to get use to

Secret of Mana... then FFX

I liked the turn based found in FFX, being able to see how your action would effect that characters next turn was great for strategy. Being able to time when you would unleash your biggest attacks so that you character wouldn't be down for to long and compromise the team was great. I liked that system so much that it made Lord of the Rings: The Third Age, a fairly average rpg, a tun of fun. Not to mention there is just something innately satisfying about going through Middle Earth killing lots of trolls, goblins, and orcs.

Got to love the battle system in Diablo 2 also. Got the rush of real time combat, little bit of skill mixing and lots of enemies running around.

Also, Earthbound. Having your life bar drain slowly was great because someone could hit you with a massive blow and you would still have time to heal that character and save not only him but your entire groups lives with a quick heal (and also the bright colors in wavy lines in the backgrounds ^^).

I liked Earthbound a lot as well (one of my favourite games)... my only gripe is that I wish the attacks didn't all look so generic. I actually want to see Jeff shooting bottle rockets and Paula whacking baddies with her frying pan :P

Baldur's Gate for turn based, Zelda/Secret of Mana for real-time.

for me it was kotr and ff12

I've liked a lot of different battle system, but my favourite so far is FFVIII's, I still thing that the Junction/Draw/GF system is one of the best ideas ever, the only drawback being that the GFs animations couldn't be skipped, other than thast the system offered a lot of customizability and some very good boss battles.

Honorable mentions:
Xenosaga (the three of them)
Suikoden II (and therefore Suiko V, since they're the same)
Suikoden III
Final Fantasy VII
Persona 3
SMT: Nocturne

XenoGears turn based combo System. its one system that has stuck in my head for long time despite not seeing the system in any other game even though they tried to make a simplified version of it in Xenosaga it wasn't nearly as deep. 8 button combo for each charactor on your team.