What is the most stable unlimited host? Do you know any?
Say marblehost.com seems to be the best, am I right?
Any other standpoints?

there is no such thing as unlimited host, there is limited some how. i have been with dreamhost and hostgator on their unlimited plan and it last only a few months before their sell rep ask me to upgrade to vps/dedicated server or getting my account closed, then they throttle my account to probably 5bps line. also, both hosting limited my account to have no more than 250000 and 400000 files per account.

The main thing is the company you have a deal with IMHO.

I have seen nice unlimited offers from ultrawebsitehosting and aspnix, they seems to be nice for me.
As least you mat try them to see how they work in reality. They cost not much.

Marblehost is a great choice.
This company has provided their services for more than 10 years with no problems!
Many sweet reviews can be read about them.

I know this company has many positive reviews and I think you may try them top see how good they are in reality.

i heard about unlimited reseller hosting but not about shared hosting.

The term unlimited doesn't exist in the web hosting industry. It is just a trick to lure customers and make them sign up for an Annual Term. Somehow, you will be restricted either on bandwidth usage or CPU and RAM usage. Read their TOS and SLA carefully, you will get to know lots of facts.

Marblehost is rather a reliable unlimited host whose services are stable and affordable.
Uptime is high and support is helpful and active.