is coinbase.com is good site i have heard that site is not working properly...? is there any other site we can get good wallet without any problems......?
If you're strictly talking about online wallets, then blockchain.info is a good choice where you have control over your private keys. (They had some security issues recently which exposed some private keys, but it has apparently been fixed now).
Otherwise I would strongly recommend getting a desktop wallet like MultiBit, which is easy to use and there's no fear of losing your coins to a website hack or fraud.