When we started writing this spotlight we had no idea how many good mods there were for Unreal Tournament 2004. Seriously, each of those mods is a complete, impressively polished game - free and made by fans, for fans! We haven't gotten enough time to run through them all so please consider this more as an example what can be done rather than "the best" list.
This total conversion does the impossible - it's changing an FPS into a third-person platform game featuring one of the icons of gaming. The mod is very enjoyable, well polished and... aw, just check out the tech demo and you will know what I mean! :)
Like every game with a good modding community, there is a Star Wars conversion and this one is just great! The game mechanics are objective-driven and you can choose from different classes, each with its own unique equipment. You can take part in Battle for Endor and fly an X-wing into the freaking Death Star! Because of this this mod I was completely awestruck! Of course You are welcome to disagree but You would be wrong ;)
One of the mods, which are still popular to this day. There are two teams, Terrorists vs the Good Guys. The first like to blow things up, the second team doesn't find it to be such a good idea... We have a minor disagreement that can be solved only by large quantities of lead. I really don't know why, but this thing is more addictive than chocolate! I just wanted to check this out, 30 minutes tops and after two hours it was 5 p.m. and I had to leave work. ;) Check the trailer here.
In this mod you can fly a dragon and fight midair battles... You still here? Not downloading the conversion already? So let me just add a possibility to chose from 10+ classes including a fireball spamming Sorcerer, a blood-thirsty berserker and a warrior in full plate armor. This is not all, in siege mode you can take control over a catapult and tear down enemy walls. There is more! You still there? Check the trailer here.
Marines and man-eating aliens never got along very well. Alien Swarm is one of the possible scenarios of human-alien encounters. You take your squad to the most dangerous parts of this alien-infested planet and your job is simple - kill everything in your path and try to stay alive. This mod is really enjoyable when playing with your friends, I highly recommend it! Here's the trailer.
In my opinion the best setting for a horror story is in space, because like someone said, “no one can here you scream”. Hollow Moon takes place on... the Moon. There is a base there where something went very wrong. This game doesn't have a standard storytelling like in most games, like the author said “this mod is an audio-visual and game style experiment“. Great music, great setting, great execution. Try it out and You will not be disappointed. Watch the trailer here.