Hmmm... tough question. I have a couple of nice .me domains, however I wouldn't have thought they have much value. For example, I have warburton.me, warburtons.me and droitwich.me (little town near Worcestershire).
I have hackersarenotcrackers.com and
hackingisnotcracking.com which I have setup with a little microsite explaining the differences between hackers and crackers.
I also have adz4.co.uk and adz4.com - I was planning on launching some kind of classifieds site but didn't think I had much chance of competing with the big players like craigslist.
I think my worst domain is nakedcarwash.co.uk - a domain I registered during a crazy caffeine fuelled Friday afternoon that I have no idea what to do with! it's either that, or
swearalot.com which you should definitely not visit while you're at work or if you're easily offended
I don't think my portfolio has a lot of value as long as the domains remain undeveloped, however I want to start developing some content sites in the near future and see if I can get some value in there.