Another one to check out is coinbase.com
I can't recommend coinbase.com as a wallet. They are probably fine for purchasing or selling bitcoin, but you really shouldn't keep your bitcoin there any longer than you have to for the purpose of the transaction.
With coinbase.com, you have no access to your private keys, and coinbase.com has complete access to the private keys. This is a very risky situation.
Essentially they are not "your" bitcoins while they are at a coinbase.com wallet. You have given your bitcoins to an unregulated, uninsured, complete stranger. Those bitcoins for all intents and purposes then belong to coinbase.com, and not you. For making this donation to them, that complete stranger has promised to honor any request you might make in the future to send an equivalent amount of their bitcoins to any particular bitcoin address. That really isn't much different than just sending your bitcoins to my wallet and having me promising you that I'll send them wherever you want in the future. Would you be willing to do that?
Fortunately with blockchain.info, you have full access to your private keys and blockchain.info only has access to an encrypted copy of your private keys. They don't have the encryption password so they are therefore unable to do anything with your bitcoins without your permission. The worst they can do is delete your wallet, and as long as you keep a backup of your blockchain.info wallet somewhere you can still access your bitcoins if they do that. It's pretty much the same as if you were to encrypt your private keys with a complex and secure password, and then send me (or dropbox, or google drive) the encrypted file to hold on to for you without sending me (or dropbox or google drive) the password. The worst I (or dropbox or google drive) could do would be to lose the stored copy of the private keys. As long as you had your own copy that wouldn't really matter much. If you never give me (or dropbox or google drive) the encryption password, your file is safe even if I (or dropbox or google drive) get hacked.
