Definitely Dan.
Mayson was actually a plus because I remember during Lucky Leon she wanted to take Clark to a play, and Lois was like, "Nope, we have plans," and bam there's the first date.
Dan was a serious hinder. Granted, Clark had a lot to do with it because his timing was just *terrible* with rescues, but it sort of thrusted Lois into Dan like, "Hey, he's there for me when I need him, and Clark's not."
My $0.02
Jen