There's a lot of options, really. I bet the second hand market is pretty big since the introduction of the Mediator.
You could always get a Mediator and a Voodoo PCI card, this will of course be pretty expensive.
I have two major recommendations:
- Buy a Zorro 3-enabled card.
- Don't settle for less than 4MB of graphics memory.
I've heard only good things about CyberVision64 and Picasso IV cards. I've got a CV64/3D myself. It's a bit sluggish for games but productivity applications zip along quite nicely.
Then there's the minor recommendations:
- If you can, get a card with a pass-through and scandoubler for your AGA signal. This will let you use the VGA monitor for both HW-baning and RTG software.
- Try to get a copy of TV Paint. It's sweeet and very fast even on my A1200 with a Z-IV busboard. :-)