Any assault map qualifies, but a special mention goes for AS-Overlord, the recreation of the D-Day event of World War II.
CTF-Face, a.k.a. "Facing Worlds". An asteroid in the middle of space with two towers at each extreme, with the skybox above consisting of nothing less than Planet Earth in the distance, easily taking up half the screen. It has plenty of spots for snipers, so getting the flag back to the base is an arduous and difficult task... for people who haven't mastered translocation. It's a map so popular and trascendental it keeps ranking among the best multiplayer FPS maps of all time even 20 years since the release of Unreal Tournament itself, guaranteeing an appearance in most of the following games since its release, most of which have been hit-or-miss. The map description of the 2004 version describes the arena in one of its many incarnations describes how it works and why it's so popular:
One asteroid. Two towers. Ten thousand headshots.
DM-Deck16][, a remake of the original, with some extra changes.
DM-Morbias][, another remake of the original one for Unreal, this time with an extra redeemer.
The last match is a 1on1 match against Xan in DM-Hyperblast: a ship going hyperspace. Notably, Xan is a challenge because of the game's (at the time) excellent A.I. (With Dynamic Difficulty for him to boot)
DM-Barricade, a castle in the first Tournament... that's floating. In a lightning storm.
DM-Phobos: One of the most evocative and disorienting, since the skybox rotates with a panoramic view of Mars.
Several of the combatants have awesome feats in their careers, with solo-combatants and entire teams being (composed of) highly condecorated veterans.
Deathmatch!Slain's description:Slain fought with the 47th Mechanized Imperial during the First Necris Invasion.
Deathmatch!Annaka's description:Annaka is a premier demolitions expert. She masterminded over 20 covert structure hits against the Skaarj in less than a year and advises the NEG 'WetWorks' Board on Amphibious Arms Deployment.
Deathmatch!Arys's description:Arys is a field commander from the 12th Mechanized Imperial. She was selected for Tournament play after she single handedly killed 8 Skaarj with an energy knife during the battle for the Orion Stormwatch Outpost.
Farham's description:Farham fought with the Earth Defense Force during the 7 Day Siege, Earths darkest hour during the war. He was solely responsible for the destruction of the Skaarj Skriith Class Dreadnaught Krujhlok and is a highly decorated veteran.
Drimacus's reaching the top of the ladder by starting from the very low levels, unlike other warriors. You encounter him in the very last match of the Deathmatch ladder.
Malcolm being "FenTech's finest creation". Considering he went on to become the nine-time Champion of the Tournament (and, in a meta level, the Series Mascot with later installments), he definitely is.
The sole fact that the N.E.G. managed to create Skaarj Hybrids and Liandri even got to have a full-blood Skaarj in the Tournament. Consider that we're talking about a race which brought Earth down to its knees.