Quake: Arcane Dimensions (mod)

I've been playing a lot of Quake map packs recently. This is far and away the best I've seen. This is to the point that I'd say this free mod is hands down a better experience than similar indie games you have to pay for like DUSK and Amid Evil... and I like Dusk and Amid Evil! Not ALL of the maps are home runs, but some of them are. And the ones that aren't are still good.

The link here points to version 1.5. That's an old version. As of the time I'm writing this, 1.7 is the lastest one. I think the difference is the addition of completely new maps, so be sure to download the right one.