Experience.
Common sense.
For one, I would assume that ComicCon is a trademark. Quite a strong one at that.
I would try to delete that domain as quickly as possible to avoid repercussions.
Look at your domain names objectively;
- If you didn't already own them, would you actually want any of the domains you advertise if they were for sale for just £50, £35, £25 or even £10 each?
- Why would you want them?
- How could you take this domain and make money from it?
Interestingly, if you were to actually action step 3 and develop your domain and monetise it, you have now made that 'domain' worth something.