Desert Conflict - Lots of servers, lots of people on-line playing, nice user interface, good selection of vehicles, weapons and maps, based on the classic BF1942 Mod Desert Combat. - A Classic!
<a href="http://www.desert-conflict.org/" target="_blank">http://www.desert-conflict.org/</a>
Eve of Destruction - Good amount of servers, good amount of people on-line playing, really nice user interface, great music, pretty much infantry based for the first release some maps have choppers - maps have dense jungle which is great for hiding in and knife kills!, based on The Indochina Vietnam conflict 1946-1973. If you liked BF:Vietnam you will love this! - My personal fave mod atm!
<a href="http://www.eodmod.com/" target="_blank">http://www.eodmod.com/</a>
Operation Peacekeeper - Reasonable amount of servers, low amount of people on-line playing, simple user interface, really well made maps which are very scenic. It's easy to see a lot of work has gone into this. It's based on German and Serbian war - shame not many people are playing it.
<a href="http://www.opkmod.com/" target="_blank">http://www.opkmod.com/</a>
Point of Existence 2 - Good amount of servers, reasonable amount of people on-line playing, good user interface, Very nicely designed maps, visually stunning. Again it's easy to see that a huge amount of work has gone into this mod - I'd like to play this one more.
<a href="http://www.pointofexistence.com/" target="_blank">http://www.pointofexistence.com/</a>
Project Reality - Nice amount of servers and people on-line, this is a very polished mod, nice user interface, maps, weapons vehicles, all professionally done. Can't really say if I enjoy this one or not because there is so much to learn in this mod you need to spend a lot of time on it, for example you can't just jump in a tank and drive off you need a kit to use them. It also forces you to join a Squad or you get kicked, and flags have to be captured in a certain order. It's promoted as the most realistic mod for BF2, when you get shot you have to apply a field dressing to stop the bleeding, so yes it is a lot more realistic than BF2 Vanilla. - This one needs a lot more of my time.
<a href="http://www.realitymod.com/" target="_blank">http://www.realitymod.com/</a>
US Intervention - 3 Severs online so couldn't really play it properly, I have read there is a huge update on its way and from what I have seen it does look promising but needs some work in getting people playing it, so can't really comment much on this one. - Kinda Dead!
<a href="http://usi.jarhedz.com/" target="_blank">http://usi.jarhedz.com/</a>
That's all for now - add your opinions on the available mods
</a>
(scaredy cat panic 
)