ive got the thor knee pads i think they are called force(about 80 bucks). i like them but i dont have any experience with anything else. i also have the 661 2x4s i dont much care for these b/c its like a sleeve and cuts off the circulation in my arm above my elbow.
another vote for the thor force. I absolutely love them. Once riding I don't notice that they are on and they don't move around at all. I'm not sure if they're too bulky for you, but I wont ride without them now.
Ive never had good luck with elbow pads. They all either give me major arm pump and/or slide down my arms with vibration and jumps. I think this is the case for most people, because I hardly see anyone wearing elbow pads.
If someone comes up with a pair that dont constrict big forearms like a python and slide down they will make a fortune.
Ive had good luck with the fox knee pads with the hard plastic shin guard and knee cap in the past. Very comfortable and pretty good protection. Most riders I think are sucking it up and getting knee braces nowadays though. They start around 150 or so for a pair now.
Remember the good ole days when every new pair of pants came with knee pads? And had a pocket to insert them into?