Hemp protein – dry and chalky, tastes terrible regardless of what you mix it in (water, milk, juice). I haven't tried any of the flavored options – I get the Trader Joes hemp protein (believe unflavored but have hard time believing flavoring it would improve it much)
Brown rice protein – dry and chalky, tastes better than hemp protein and isn't too bad mixed with juice if you get vanilla
Hemp + brown rice (my own concoction) – I like hemp protein but not the taste – makes it more tolerable in my opinion.
Vega – I've tried the berry and the vanilla flavors. Tastes a lot better than hemp or BR but it's very expensive and still, it doesn't taste that good. Berry and Chai flavors seem limited in mixing options – I'd stick with vanilla.
Ultimate Meal – Cheaper than Vega but more expensive than hemp, BR and taste wise falls the same. Doesn't come in flavors.
In short, I find Vega to taste the best – but it's expensive and it still doesn't taste that great. If you want to try Vega, you can get single serving packets to try it out. Hemp and BR can find in bulk bins at whole foods, PCC, other natural markets. Ultimate Meal I think only comes in two sizes of tins.
If your wondering – I usually mix these proteins at home into smoothies – you can do amazing thinks with a blender, a banana and a few other fruits/veggies and you forget about the taste of the protein.