I've tried both whey and soy protein powders, I also have used one that was made from seaweed which was pretty good actually. I'm borderline allergic to dairy, so I'm always looking for other ways to get protein. I think that dairy (whey) proteins are supposed to be better for weight loss, but I think all of them are efficient for building muscle.
If you're just looking to up your protein intake, you might try cottage cheese, Greek yogurt and/or nuts. There are also some decent protein bars on the market. Tuna is also a great source for protein, some vegetarians eat fish and others don't, and I don't really know where you stand.
Starting weight: 244.6 lbs. 10/01/09
Pounds lost: 80.6 lbs
Current weight: 164 lbs
Goal weight: 120 lbs
Weight to go: 44 lbs
Goal Date: 1/1/13