Mycomicshop.com has the majority of the alien comics. I just finished my collection by buying all the rest of the stories from the DHP miniseries.
But I did that just to "finish" what I started. I started buying them when I was twelve or so, and continued to buy them until this very year about nine years later. Of course I agree lots of the stories are silly, but when I was young they did get the imagination fired up.
Whats kind of bad is that I was collecting the novels too, and actually ended up with Berserker (fortunate enough to walk into barnes and noble and see it right there in front of me). I lent it out to a friend that forgot to give it back and MOVED away with it.
I could probably get it back if I asked him. I just don't feel like driving to Tennessee to get it.
Actually collecting them was more fun than reading half of them. :\