Not a collector, but I have found a few favorites over the years, wondering how popular they are with enthusiasts:
Delfonics wooden ballpoints- just for the desk since they aren't too tough, probably the finest point I've used, but most importantly have a satisfying click
Caran d'Ache 849 ballpoint - using the same one for 5-6 years now at manual labor type work, only one small dent so far. Uses 'Goliath' cartridge
which is presurized like Fischer's (was mistaken here, it's not pressurized) and also works on coated papers & lasts quite a while.