Oh wow that is quite a bit. I've owned my fare share of domains as well; I honestly wish I would've kept a bit.
I don't exactly buy domains because they're "great to resell" though. Two I definitely regret getting rid of would be Slyth.net and Demigra.com (Fun fact, Doom was Slyth.net to begin with, but I changed the name when Doom.sx popped into my head one day). I'm a big fan of taking something random or unique that I come up with and giving it it's own worth and identity; what I aspire to do with Doom.
Is reselling domains actually good business/money? I've considered actually getting into it, since I spend most of my time developing sites like this in my freetime anyway.
Oh also, for those who don't know one of my side projects is:
http://wurldz.net/ which is just a sort of blog site for members to vent almost anonymously about any thoughts they have no matter how ridiculous, the idea is that there's not many platforms that allow absolute unfiltered/uncensored discussion so Wurldz would be just that; while also appealing to Support Hotlines and having a chatroom for "lonely" individuals to find comfort in conversing with strangers (safely of course.)
I also plan to outdo DeviantArt and Newgrounds, and all competitors with my own unique Art sharing platform after Doom is fully developed to the degree I'd like.
Hehe I know I strayed a little off topic, but felt like sharing a little.
Those were my favourites. I used to do it for a living, but it's not very lucrative anymore unless you have a really good extension. 