I currently use a Boss FV-500H as an expression pedal and it works great. It has adjustable sweep, resistance and overall is built like a tank.
I've also owned a Roland EV-5 (no issues with it just wanted something more solid) and an Alexis F2 (cool as it has a few different option but just felt weak).
I've used a Nose expression knob and a t1smyne mini expression knob. I felt that they worked well but not great. (even with a big knob and big ol feet I found myslef using my hand).
I'm looking into getting an Expressionator as I have a couple more pedals that I wouldn't mind having that option avaliable.
Typical EBOW,octave,fuzz,synth,poly-whammy,freeze-gliss,sample-reduce,MODE 7,flange-chorus,super phaser,FAT-filter,lo-fi delay,cave reverb,lo-fi looper,space echo,Chansey reverb/poke-freeze bassist