I like pea because it can be mixed in soups and the like. I'm not a fan of sweet protein powders and I avoid soy due to my thyroid issues. However, pea protein has often been toyed with to remove absorption inhibitors.
I just drank a sample mixed with water and I almost died, but seriously the natural flavoured powder, is probably best mixed in a soup or tomatoe juice. I'm getting a bottle of the meal replacement (hemp), which not only contains the protein but several other beneficial items, just as an added extra. But yeah it appears as though hemp is numero uno!!!
My boyfriend and I train alot, we use soya protein isolate or pea protein! I've also taken something which I thought was quite good - an amino acid supplement called L glutamine! It can be used in conjunction with protein and supposedly makes your body more efficient at utilizing protein and aids training capacity and recovery etc. It's also said to help your immune system as L glutamine is an amino acid that plays a part in immune system health.
I noticed I had a fair bit of energy using it (I know not all of these products work and it could be coincidence etc, but I would happily use it again) and I didn't notice any side effects other than a slight loss of appetite!