Personally, I just find it kind of amusing that Shaun Cassidy is shown or referenced on six of the 16 covers. The next most frequent cover guests are the Hulk (five covers), Spider-Man (four) and Peter Frampton (three)...

Also worth noting is the Linda Ronstadt cover. Oh, sure, it's a good likeness of her and the fact that Captain America and Dr. Strange are playing guitars behind her is chuckle-worthy. But I think it's more entertaining to see C-3PO playing drums behind them!
Finally, does anyone actually have a copy of #12? I want to read up on those "Albino Roach Jokes!"