I like them all to some degree, so it would depend on the rest of your roster and what you need. I like Bennett's potential but don't think you necessarily need him with those other TEs.

Probably like Powell a little better than Riddick because Powell should get some carries. Then again Forte could steal away Powell's receptions too. Riddick more one-dimensional but should still get a ton of catches. I think I like Powell as someone who has potential to get a lot of work if Forte goes down. Riddick probably more of an immediate help. Powell could have trade value to Forte owner too.