2d PSP games

[Psyduck]

Have just got a PSP again, and so I'm not really up on what's good and what's not. Seems to me that most of the 3d games are just pale imitations of console games with poor gfx and frame-rates, whereas the 2d games look loves. I realise that's a bit of a generalisation, and so I'm not looking for a fight!
Anyway, can anyone suggest some of the best games to go for? Stuff like locoroco, patapon, prinny all look good. Any decent 2d shooters? Platformers?

And feel free to mention any great 3d games too if you have to! Other than the obvious ones of course...

[abigsmurf]

Symphony of the night, megaman x, megaman powered up.

There isn't a huge amount of 2D platformers because Sony did their usual restriction of 2D titles for third party devs.

[egparadigm]

Ultimate Ghosts 'n Goblins!

[Darwock]

For shooters you can take your pick, there are loads of compilations of classics (mostly Konami though). I'd recommend Parodius Portable myself, but there are also Gradius & Twin Bee collections as well as others I think.

I'm not sure if it's what you're after but Lumines is obviously 2D as well

[Phar]

Princess Crown