Definitely the PS2 for me! Tekken Tag Tournament, Fantavision, Ready 2 Rumble Boxing: Round 2, Street Fighter EX3, TimeSplitters, DOA2: Hardcore and Dynasty Warriors 2.

People may not remember how poorly some of these launch lineups were received. Perhaps somebody (not me) would be willing to put some metacritic scores up....

SSX was the one game that saved the PS2 lineup (bought the game and couldn't even get a console on day one!), PS1 was pretty "meh", I was underwhelmed by Resistance. I'm going to say Vita by default. I was pretty pleased with it, right from day one. Didn't get a PSP until 2009 so I didn't experience its launch games when it was still fresh.


Vita.

Pocketstation

Real answer is ps1, why?  Because it managed so much despite being sonys first attempt