Exposure Joystick light (when married to a helmet mount). Has served me well for a few years now. I think the light being at head height has made a difference in avoiding some driver errors.
Cateye Velo 8 'puter. Been using mine for about 8 years now. 2 Battery changes. No problems since I learned to dab a bit of vasaline on the contacts to counteract biblical weather conditions.
Altura Airstream jacket. keeps me nice and toasty in the cold weather. A snip at a penny under £40 when I bought it.
Specialized BG Equinox gloves. Comfortable, warm, could write tickets in them when used on cycle patrol. Protected my delicate mitts when I was required to defend myself. Sadly I have ridden mine into oblivion.
Tacx Spider workstand. A good, secure work platform that doesnt stress the tubes.
Continental Contact tyres. I'm saying nothing that will tempt fate