Hey, don't knock immortals
Immortals has its uses, it exists because it serves a purpose - it takes some other mutes to see it though. For example, try playing it with CoilJump - coiljump is a mod about juggling - every time you shoot a player they airjump. Each time a player is airjumped without touching the ground, the attacking player gets something - a frag, health, etc. On the fifth airjump without touching the ground, they explode. If you want to play with only the airjumping, use immortals - I recommend throwing in some weapon mods for flavour.
Heres another mod-mix recipe - Redeemer Arena and Immortals playing LMS or CTF on a space map with little to no walls to brace yourself up against (CTF-FACE ][ works quite well). Its all about blasting the other players into space by brute force of explosives. Also, you can rocket jump clear accross the map. Damn good fun.
Many underated mutators become cool when you consider what you can mix them with (Kill-2-heal and LMS is ****ing awesome, and Kill-2-heal got a terrible rating).