If they are in a relationship: I have to admit that I have been with a couple of married men (at swingers events). The ones that bothered me were the ones playing alone, plus that latest asshole... However, I feel bad about having done this. I really only want to be with single men - although if they are at a swingers event AS A COUPLE, I don't have as much guilt over that. I am in an open relationship myself but my LTR guy and I both know that we will never be anything more than what we are now. Besides, we now live several states apart. But we will always be good friends. For real dating, he MUST be single! I'm not a homewrecker.
Within a certain age group: I prefer younger men (within reason - no underage!). However, my LTR guy is 11.5 years older than me.
Has to have a good job: I want someone with a steady job, and I have to admit that part of that is because I DON'T have a steady job right now. Ideally it wouldn't matter who made the most money, but right now if he makes the same or less than I do, we'd not be living very well! My LTR guy makes a LOT less than I do, even now - he only makes around $200 a MONTH. Can't live on that!
Really good looking: I like a good-looking guy as much as the next person, but there has to be more to it than that, and an average looking guy with a great personality is much preferable to a good-looking guy with a bad personality.
Has to be hung: Somewhat necessary for me due to my physical build, but one average sized guy was REALLY good with his hands...