I could be boring and mention CAD and all those just plain terrible ones drawn by creeps (like Boston and Shaun), but I'll just mention the ones I used to read because there were one or two things I liked about them but I eventually realized they were just not remotely good.
*Wapsi Square - I read this one for about a year before realizing that the author had no idea what he was doing. The plot went veering off in so many different directions, ideas were just abandoned, characters completely swapped personalities for no reason, etc. Also I'm really getting tired of girls showing how empowered they are by acting sexy.
*Sore Thumbs - this one did actually have a couple funny moments hidden in there, but it's like a Skinner Box: you just keep reading, no matter how much it makes you cringe, hoping to find one of those funny moments again, but you're always disappointed. I broke free eventually.
*Manly Guys Doing Manly Things - this one also has good moments, more than Sore Thumbs (and the art is much better), but overall it's pretty dull. Videogame/meme based jokes are just rarely funny anymore. This one isn't terrible, just...boring.