I'd have to say go for whole eggs. Don't be scared of the cholesterol (unless you're prone to high c) because your body needs it to make more testosterone, which is the hormone that promotes muscle growth. I've been going through a dozen eggs a week for the last six months or so and although my weight has stayed about the same, I've packed on a lot more muscle while dropping half a pant size.
Fish and goat are also really lean protein sources. Goat is even leaner than chicken and IMO has a better texture than chicken or beef and soaks up marinade really well, so it ends up being a really tasty high protein dish as well.
For those of you using protein shakes, I'd recommend Trader Joes vanilla whey. It's got pretty significant amounts of vitamins and minerals so you can safely sub them for meals every now and then.
Good luck to everyone on your own journeys.