Personally, flecktarn is my favorite. However, digital camo is easier to get in the U.S. This is especially true if you have a local surplus store, like I do. I recommend getting flecktarn from one of these two websites:Hessen Antique, a German military surplus store that has a U.S. site, and ASMC, so-called: "the adventure company." These are only personal recommendations; use what works best for your kind of gameplay. Find something cheap. Then you can experiment with other camos.
Flecktarn is amazing, but more recently, concamo is proven to be the most effective camo to be made yet.
There is also a brown version, but I can't find it for sale.