My favorite fat sources include:
Fish Oil (pharmaceutical grade)
Extra Virgin Olive Oil (Italian Olive Oil Only :)
Unrefined Macadamia Nut Oil
Raw Almonds and other nuts
Organic nut butters (peanut, almond, macadamia)
Whole Eggs (from hens fed a vegetarian diet)
Fatty Fish such as salmon or swordfish
Flax seed oil (in moderation)
Evening Primrose Oil
It's important to balance Omega 3s with Omega 6s. Omega 3s reduce inflamation while Omega 6s promote it. While you would think that an anti-inflamatory effect would be beneficial, keep in mind that muscle growth is, by nature, an inflamatory process and too many anti-inflamatories (whether from diet or drugs) can hinder the muscle building process. Balance is key.