Mod descriptions can be found on the download page.
Gameplay Overhauls:
First Person Mod:
http://www.gtagaming.com/downloads/gta-iv/script-mods/2635
Simple Native Trainer:
http://www.gtagaming.com/downloads/gta-iv/script-mods/2115
Cautious Drivers:
http://www.gtagaming.com/downloads/gta-iv/script-mods/9052
Blood and Heal:
http://www.gtagaming.com/downloads/gta-iv/script-mods/9051
Bullet Time:
http://www.gtagarage.com/mods/show.php?id=6219
More Liberty:
http://www.gtagaming.com/downloads/gta-iv/misc-mods/4235
Graphic Mods
Iceenhancer (Strongly recommended):
http://www.gta4-mods.com/misc/icenhancer-12---enb-graphic-mod-f9236
Mod IV Real:
http://www.gta4-mods.com/misc/mod-iv-real---graphic-mod-f9496
Clean Car Reflections:
http://www.gta4-mods.com/misc/mod-iv-real---graphic-mod-f9496
Other
Supercar/Exotic Car Pack:
http://www.gtagaming.com/downloads/gta-iv/vehicle-mods/9191
GTA San Andreas Weapon Pack:
http://www.gtagaming.com/downloads/gta-iv/weapon-mods/9230
Gameplay Overhauls:
First Person Mod:
http://www.gtagaming.com/downloads/gta-iv/script-mods/2635
Simple Native Trainer:
http://www.gtagaming.com/downloads/gta-iv/script-mods/2115
Cautious Drivers:
http://www.gtagaming.com/downloads/gta-iv/script-mods/9052
Blood and Heal:
http://www.gtagaming.com/downloads/gta-iv/script-mods/9051
Bullet Time:
http://www.gtagarage.com/mods/show.php?id=6219
More Liberty:
http://www.gtagaming.com/downloads/gta-iv/misc-mods/4235
Graphic Mods
Iceenhancer (Strongly recommended):
http://www.gta4-mods.com/misc/icenhancer-12---enb-graphic-mod-f9236
Mod IV Real:
http://www.gta4-mods.com/misc/mod-iv-real---graphic-mod-f9496
Clean Car Reflections:
http://www.gta4-mods.com/misc/mod-iv-real---graphic-mod-f9496
Other
Supercar/Exotic Car Pack:
http://www.gtagaming.com/downloads/gta-iv/vehicle-mods/9191
GTA San Andreas Weapon Pack:
http://www.gtagaming.com/downloads/gta-iv/weapon-mods/9230