Excellent idea to put the games in the OP!
My recommendation:
GTA: Chinatown Wars
The driving takes some getting used to but besides that it's everything people that like the PS2 GTAs are looking for. There are rampages, sidemissions, awesome characters, superb and humourous dialogues, races and whats most important a big variety when it comes to the main storyline missions. But what really needs to be implemented in the next home console GTA is the highly addictive drug trafficking. I haven't played a mission in a few hours, only sold some acid, weed and coke (no heroin, don't sell that shit
)
GTA Vice City Stories
To keep things short: It's my second favorite GTA (right after SA with GTA 4 being last)
It's surprisingly long for a PSP game, graphics are good,
there are some slowdowns (like in almost every PS2/PSP GTA, OST is excellent, the MC maybe the second best in any game of the series and it adds some nice elements like taking over businesses to get some extra money.
However I only played this on the PS2. I'm pretty sure they didn't change anything, but keep that in mind.
Popolocroisis looks and sound awesome think that's gonna be my next RPG.