Trade ins?

Hi everyone I'm thinking about trading in my ds games for new ones? (I live in Australia btw)

I have Simpsons, LoZ Phantom Hourglass, Brain Training 1, Nintendogs & Ace Attorney Phoenix Wright (finished all apart from phoenix)

Which should I trade in?

I was thinking I'd get Professor Layton when it comes out ... and maybe something else like kirby or something?

I don't know ... you guys help me plz :)