I have to get the obligatory comment out of the way first.
Judging from this and your other posts you seem to be looking to make a Battlefield-style game. My first recommendation is to start with a mod of one of those games (Battlefield 2 would be the starting point since BF3 does not have mod tools yet AKAIK. Crysis Wars may be a decent starting point as well). Make some maps, vehicles, weapons etc and see how far you get.
If after a few years (that's how long it takes most mod teams if they ever even reach completion) you actually have a decent mod you can start working on an actual game, maybe even with some funding from investors! In which case choosing the engine will be the least of your worries.
If you choose to ignore this advice (which you almost certainly will...) then I would say the Torque engine would be an excellent place to start. It gets somewhat maligned in these parts, both fairly and unfairly, but it is extremely well suited to making games of the Battlefield style. It has excellent networking code and There is a lot of built-in logic for guns, vehicles, grenades, mines etc as well as environmental systems such as weather, forests, and rivers.
People run into trouble when they try to make... well.. anything else... But it is certainly well equipped to handle that genre. And completely free now with no hidden gotchas like the free versions of UDK, Unity or Cryengine. And perfectly good graphics rendering too, if you feed it some nice artwork.
Finally if you are absolutely dead set on BF3 quality graphics and environments and have the skill and manpower to pull it off *ahem*, well then Cryengine 3 is probably a good bet as it's designed with those sort of environments in mind, has one of the very best renderers in the industry and seems to have solid net code.