Domainz.io - Premium domains, for not so premium prices
SideProjectors - Marketplace to buy and sell side projects
Newsy - Monetize your un-used domains and turn them into your own content aggregator with 0 code!
Transferslot - Easily buy and sell side-projects
DomainWatch - Domain Monitoring Made Easy
1Kprojects - Neglected side projects for less than $1000.