I've played UT, UT2003 & UT2004 avidly for years. They're fantastic games, each with their unique graphics and gameplay merits. Nowadays, I keep switching between UT & UT2004.
But UT3 hardly gets a look-in. Why?
Because of the feel. While it has a technically superior rendering engine, it just doesn't feel as nice or engaging to play. The characters just make an annoying agressive sound and the artwork on the maps just isn't as pleasing on the eye. The standard maps tend to look very dark and lack colour, so aren't nice to look at.
When I go to LAN parties, it's always UT2004 that we play, so I'm not the only one that's noticed this.
Funny how after all this time the original UT still plays very well, not losing any addictiveness and still looks smooth and impressive - even more so with quality settings maxed out and high res modes on modern hardware.
And those DX7 graphics actually have quite an appealing retro look to them now, while still looking awesome. And best of all, it now costs a pittance to buy!
Just check out the Steam UT bundle.