I've been somewhat playing UT since it 1st came out, a bit longer than that as a friend of mine was beta-testing the demo version (least I think he was) before the official release.
Not until folks started customizing maps did I get hooked.
The 1st map that ever really grabbed me, and has been my favorite to this day, is HallOfGiants. Made originally for CTF, there are now versions for literally each gametype and they come in a wide range of variety; including DM-HallOfGiantsExtreme which Helen fixed after years of my being told it couldn't be fixed.