I strongly recommend avoiding wallets. I keep all my coins in cold storage addresses.

I only use a wallet (Mycelium or Coinami)to facilitate transfers. I never leave anything in a wallet for longer than it takes for the transactions to be confirmed by the network.

I absolutely never allow my coins to be in anyone else's possession... no online exchanges, etc. When I buy or receive coins, it's always straight into cold storage addresses I created on an internet incapable computer and printer. When I sell, it's face-to-face for cash on the spot.