Oh thats hard:
My very personal hit list:
1.) SEB Nam 2 (i am a Nam Maniac)
2.) ECP Enhanced Configuration Project (because it works with all OFP stuff)
3.) BAS (Great AddOns, Great Team)
4.) LASER's Russians (Perfect !)
5.) snYpir's Support Package
6.) German Army Mod (BW Mod, well at least i am German)
7.) CoC (they really change the face of OFP)
8.) Invasion 44 (World War II, even if i would like more work together of the teams)
9.) Finsih Defense Forces (Great total conversion)
10.) Lego Warez ;D
Oh, already ten..., Not to forget (CM Weapon Pack, Sucheys Marines, Inq Weapon Pack, TOW, Operation Frenchpoint, the SA 13 AddOn, Vits and Footmunchs Planes)
Greatings Kuro