I've been using http://www.kraken.com of late and it's been great - no problem wiring money to/from my bank account, easy to convert between LTC and BTC and market orders close immediately.
I've only been trading in small BTC amounts though so not sure if you'd hit liquidity problems if trying to trade large amounts (kraken's volume is quite a lot smaller than the bigger established players like bitstamp)
I started using bitfinex recently. Other exchanges I've used have had miriads of downtime, and I just moved off campbx because their site is so slow (and their market cap has shrunk huge). The other plus is that their fees are often half of other exchanges, I went from a .5% comission on cbx for sales to a .15%.
Bitstamp is also good, I hear, but I just went with finex because their fees are lower =P.
I think it is important to use an exchange outside the US though, because I expect the fed to start going Orwell on any bitcoin company soon.
There's also the Canadian https://www.vaultofsatoshi.com/, which seems to be top notch as far as the tech (multiple 2FA options, OpenPGP cryptography for email, etc.).
Coinbase recently imposed a kind of ludicrous $3000 a day outbound limit on accounts that had previously been limited to 50 BTC/day.
Removing the limit involves buying coin from them, waiting 30 days, and solving some seemingly impossible credit report based identity quiz (some people report passing after 10 tries, you're limited to one try per 24 hours).
We did that back in the online poker gambling days. The casinos would throttle USD withdrawals, so that the players would be forced to wait and end up losing their chips by playing more. Physical casinos do this by attaching hotels next to the slots. This sounds similar.
I've only been trading in small BTC amounts though so not sure if you'd hit liquidity problems if trying to trade large amounts (kraken's volume is quite a lot smaller than the bigger established players like bitstamp)