Those of us who don't (or try not to) buy 3rd Party figures still want an official Shockwave.
But Blitzwing & Astrotrain definitely seem like other logical and awesome choices as well.
On an unrelated note, who has experience selling parts of their collection to the local shops? Who generally gives the best value? I've sold things to Metropolis, but not Toy Traders or (new) A3U.