i like a wallet that doesn't take up a lot of space on your hard drive. online wallets are more dangerous but they ahve the advantage of your btc being there if you need to sell quickly. If you want to hold through ups and downs, then offline wallet is better.
Wow, peculiar perspective.
Anyway, Electrum has better availability than any online wallet, since you can connect to one of many servers. Also, Multibit can sync with the network pretty fast.