Natwest aren't too bad. The online system is simple enough to log into, but you need a card-reader thingy (they send you one) to set up a few things, which is a slight pain in the backside. However, I've not had a single issue with Natwest as of yet. In fact, almost quite the opposite.
Conversely, Lloyds TSB's online system is awkward to log-in to, but much easier to use in the sense of setting up payments. However, as a bank and a company; they are horrible, useless ********* and their call-centres (minus a few) are pretty much full of people you can't understand. If you want something from them, they drag their heels, but the second you owe them a penny, they're banging on your door. More than once, I've ended up with charges due to their own sodding mistakes and they still refuse to refund. If you can, avoid them like the plague. They truly are a horrible, horrible bank.