It depends how we're classifying interesting and boring.
It could be argued that the X10 is an incredibly boring route as it's just a straight road with a few stops, but as I've mentioned before it's quiet interesting sitting backwards and just watching people go by in their cars, you never know what you're going to see!
I also quite like routes that go through 'dodgy' estates, it's guaranteed there'll be some drama to keep you entertained.