I've been with 000WebHost for a while now. It's pretty awesome mainly because of the zero price tag. For a free host, it has a large amount of uptime, although I would like to see it higher. Their staff care about the users. My favourite features are the ability to add unlimited subdomains and the two free MySQL databases that come with it. I prefer that because many free hosts come with only one or no databases. 000WebHost has a reliable web-mail portal. You get emailed about the latest updates, so I always know what's new, and what to expect. Unlike a lot of free web-hosts, 000WebHost comes with a free web-based file manager!

To conclude, for a free web-host, 000WebHost is the choice to take.