20GB 2G. You like the design better. It has more space. You will always be thankful for more space down the track.
You save 100 euro's. Spend it on something else cool. Buy a game or software for your Mac. Or some more music.
The 3G has backlit buttons - but the 2G has buttons that you can always 'feel', even in the dark with no problems. Both models have a backlit screen.
The 3G has some crappy games. Big whoop.
But good things the 3G has is on-the-go playlists and the dock.
Do you want the dock? If so, 3G it is. If you don't mind, go the 2G; unless on-the-go playlists mean heaps to you.
Now class, to wrap up:
What would you prefer:
100 euro's in your poket
The design you like better
5GB more space
or
On-the-go playlists
Dock
Games.
Sounds to me like 2G is best for you.