I'd recommend Vagrant Story if you're into RPGs, though I'm not entirely sure how well it's aged.
As far as FFs go, I'd recommend FF8 over 7 anyday, although most people would tell you to ignore 8 and go for 7 or 9. I think if you do get a PS1 FF game, you can't really go to wrong with any of them.
Out of the two you mentioned, FF7 is valuable to play so you'll know how to respond when crazy people tell you FF7 is the greatest RPG ever. Chrono Trigger is interesting in it's potential for different endings and stuff, but I'd choose FF7 as it has a tighter pacing overall.
The wording on the Coordinated Attack is poor for the concept I believe it's trying to describe. A team-up attack would specifically refer to the combination of two or more character's attacks/powers to form one instance of an attack as what you've described.
I believe a Coordinated attack is intended to be the separate attacks of two separate entities coalescing at a single point, being well timed to match each other but not actually complimenting each other besides the fact that they occur at the same time and place. Like ganging up on someone in an RTS or MMO PvP.
This page(Coordinated Attack) definitely shouldn't exist in it's current form and even if it was reworded properly I don't think it really refers to a proper concept.
@ImHungry: But its styyyyyylish. Just eyecandy for me. Sometimes tha'ts all you need!
I'd say they get more personality as it goes, but don't get your hopes up. It's still kind of dumb.
I'd argue that K is just about the dumbest!
It got too stupid for me when the one guy stopped trying to kill the other guy and instead made him lunch. Just felt like some weird bait-and-switch from the fantastic opening of the 1st ep. to some bad slice-of-life mystery.