I think Luxray, Staraptor and the 3 sinnoh starters could work well with mega evolutions. Luxray I'd one I was always disappointed never got one considering how early you get it in the sinnoh games and can stay on the team nearly the whole way. also feel like toxicroak should get a mega cuz if I'm being honest there's not many strong/cool poison types and he work great for combating the steel type immunity with his fighting moves