number 1 use for an amiga 600? finding an atari st user and boring them to death with how much better the hardware is! i had to endure these kind of comments all through the 80's. i bought my atari st for music. and it never got used as a midi setup would have cost £1000. still it got used for some fun games and i wouldn't have gotten one if i hadn't got it for some serious stuff.
i liked deja vu, the uninvited. (i'm still stuck on it...) they are on amiga also. i only just finished deja vu last year on gameboy colour. thats one tricky game! i didn't like the fact the games couldn't be bought like on the spectrum for £1.99 and so i never really bought software for it.
you could do some word processing. i was going to write a book. for me i would have found it nicer to sit at something with a retro feel like the amiga has. making sure it's a nice stable computer though or backing up regular.
i think a lot of the 600's uses have gone to better machines. it was a bit of a stopgap and time has moved on. for me it wasn't as compatible as i wanted. it is still a nice collectable all in one computer. and who knows what add ons may come about in the future. it won't ever lose the money paid for it. they just get rarer.
:-)