I've only tried RadQuake and NxMakaqu and NxMakaqu in my opinion is the better version to use.
RadQuake is good but the graphics are blurry due to the resolution it was playing at. NxMakaqu's graphics are much crisper and look good but are interlaced (every other line of pixels hrozontally is missing). I still prefer it to the blurry look of Rad Quake.
Both are good really and I'd have been happy with either, but since there's a choice, I prefer NxMakaqu. You can find the plain files here:
http://dreamcast.dcemu.co.uk/nxMakaqu.php
Bookmarks