Some people regret that they host their blog in free hosting, and when the host is gone, they regretted that they never make a backup of the blog database and everything is gone with the dead host.
Ultimately, even paid hosts crumble in the end. You are the only person to blame if you lose data unless the hosts ToS specify they will provide you with backups (and even then unless you want to actually take them to court over it, good luck there. Some will be honorable and provide you with the backups -- others will try charging you an outrageous amount or deny you them entirely.)
I agree, everyone is responsible for their data. Most Control Panels offer a way to backup your data in a .zip or in some other way.
A lot of free host nowadays are capable of running big sites.
How reliable are they? It will have to depends on how the fund the servers.
Of course, if the datas are important, you should get yourself a more reliable host.
My bet is that the "best free" host is hidden somewhere(probably a one-man show with very small number of clients?).
However talking about the reliability, you can't count on any host(free or paid). You need to protect your backups your own. Even the *biggest and most expensive* datacenters lost backups. There is no guarantee on them. So the best choice is to depend on your own.
Yeah, I agree with eSupun.
Even something as big as Amazon cloud, datas did corrupted after their previous blackout.
Think charting of this type isn't efficient: everyone has their own parameters and preferrings. One may like the host#1 and another would hate it