Whey protein is generally the best protein you can get (in terms of amino acid profile).

There are some good vegan powders but also some real shite ones that seem to have high protein but of low quality. One with a 70% pea protein and 30% brown rice protein blend is about the closest you can get to a whey powder. I'd be skeptical of one's that don't provide an amino acid profile table beside the nutrition facts. Good chance they're inflating the total protein with poor quality sources.

Also, like someone else said, you can consider a whey protein isolate. If you aren't avoiding dairy for ethical/diet reasons and just due to lactose intolerance, good chance you can have an isolate without blowing up your bowels.