I'll start.

1) the game would be MMO AND offline capable.

2) it would not be true real time battles. It would be based on something similar though.

3) I would implement a combo system kinda-sorta similar to Legend of Dragoon on the PS.

4) the player be able to map out his own combo with moves he can design.

5) it would have counter-attacks and reverse-combos based on those counters and counter-counter-attacks.

6) the player could control the whole team, or macro them out.

7) the player could combine special attacks and/or combos between teammates.

8) the player could strategically use the environment in defense and attacks.

9+) reserved. 

(If you have not noticed yet, I am very interested  in game design and would like that as my job description in the near future, so I NEED YOUR INPUT!)

I like the battle system of Shadow Hearts personally. A regular turn based system with a ring system so I don't get bored from just pressing buttons, a little timing based RPG really keeps me from getting bored with the system.

edit: also I hate random encounters, and my perfect RPG would have a system where you can see the monsters before you fight them. 

have a random button, when selected something new and completely random just happens in the game:-
- like instant kill the enemies including bosses.
- instant kill your whole team.
- have monkeys appear from no where and fling their poop at the enemies before instantly being killed.
- causing the game to fake a game crash during a very long battle.
- temporarily hide your save file making you think you lost it and have to start the game again but then stops you from actually creating a new file and just gives your old file back.
- scratching your disk for the hell of it.
- have your 360 RRoD on you for the fun of it/ have your ps3 overheat and turn it's self off all during an important sequence of the game.

I'd just keep hitting that random button to see what it would do next, hell it could even show some porn. LOLz

I really like the combo system from Vagrant Story so that would be a plus for me

off topic .... i would not push that button too much if i were you jake .. it could kill you !! and your family AND your dog !!

 perhaps pressing it would bring peace to the word, or cause it to implode on it's self, that or just open a black whole, all in all it'll be fun. XD

 Would you gamble with the world's life like that man ??!! WOULD YOU !!!

back on topic ... an action RPG would be my top choice ... Like secret of mana  ( specially the first one or Seiken Densetsu 3 ) anyway ... you have already some good ideas there "Blue Star"

 Yes, yes I wold, just to find out what happens next. XD

 Actually ... i Think i too would like to know what haens next .... so go ahead and do it !!!!

I love Secret of Mana. A random button would be an interesting idea. It is kinda like a rouge mages' spell in D&D that does completely random crap. From changing you into a girl, or making you hover 3 feet off the ground, among lots of other things. I am looking for a "consensus" really to get an idea of what people like. I am just curious if my ideas will strike a good chord with many gamers.

*edit - Congrats Tavin. You understand some elvish or at least have the appendix handy.