I'm tired, which leads to laziness, so i didn't read any of the replies.
Sorry if these have already been mentioned.
A PS1 game but still amazing.
I play it all the time.
Metal Gear Solid.
Great replay value there.
And of course...you can get 2 and 3 for the PS2 afterwards.
Also PS1 games:
Final Fantasy 8
Final Fantasy 9
Both good, 8 is better though.
Ok on to Ps2 games.
Resident Evil 4
Get it....just get it.
Uh...wow i can't think of any other good PS2 games right now...i've been more into xbox so...sorry.
Back to PS1 then!
Tenchu 2
Resident Evil 3
Jet Moto (Racing...on hovering jet bikes!)
uh...what else...
Legend of Legaia
Oddworld (Theres a PS2 sequel that i've never played.)
Twisted Metal 3 & 4. (Somewhat lame but still fun.)
If your still wondering, one of the best single player games for the PS2 would have to be 'Beyond Good and Evil'
Its an action adventure game that combines steal with a little combat and lots of vehicle segments complete with an open world. There is so much to do and the story if VERY involving and you really start to feel for the characters and the situations that they go through.
Been a while since I played my ole PS2 ... ( hmmm ...looks like rain on Sunday ....I wonder .... ) but ones I really enjoyed were :
Conflict 2
SOCOM Navy Seals ( all of 'em )
Splinter Cell ( whole series , time consuming but addictive )
Baldurs Gate 2
Gun ( I love the wild west stuff :crazy: )
EDIT : Mercenaries is a great game too
"Pressure makes gems, ease makes decay " - Mandalorian Proverb