Far from being "completist" I'm only snapping up games that I like on the PCE. I was lucky enough to actually start with some smashing games with my PCE GT, but I tend to so a bit of research now, so I should avoid really bad games.
The games in my collection that I would probably avoid playing are...
I guess The Kung Fu. Which is understandable, because it's more of a tech demo. First game I ever bought (chose) along with Street Fighter II. Based purely on the cover, and the fact that it was called "Drunken Master" by the shop.
and maybe Hany on the Road (also bought based on the cover) which I'm not a huge fan of.