CD32 has 2MB chipmem, AGA and cd as standard. There are quite a few cd32 games and most a500/a1200 games can be played on the cd32 from compilation cd's. No keyboard as standard means some a500/a1200 games no written for the cd32 may not work properly like Pinball dreams etc.. Expanding the CD32 (Ram, cpu, hard drive etc..) is usually very expensive as expansions are rare.
A500 will have either 512K or 1MB chip, no cd and no AGA. But you do have the keyboard and 99% of all older floppy games will work no problem. Expanding the RAM or getting a hard drive or cd-rom is relatively cheap. There will soon be the ACA520 accelerator which should be pretty cheap too. You can also get the Indivision ECS scandoubler/flickerfixer.
Put simply, if you don't want to hassle with upgrades etc.. the cd32 is a great all-rounder. If you want to spend a little money and upgrade, then an A500 with 2MB chipmem plus some fastram and a hard drive will make a great whdload machine, though some newer aga only games will not work.
