I chose to join the Imperial Legion instead of the Stormcloaks which of course meant working along side Hadvar. I ripped through all the quests and completed the entire quest list for the Imperial Legion. Fast forward to Whiterun, I'm attempting to purchase the house that's available there and as soon as I entered Dragonreach to talk to Proventus Avenicci I heard the sound of a sword being drawn behind me so of course I turned around and who was it? Why it was none other than Hadvar from the Imperial Legion.
Long story short, since I completed the Imperial Legion quests he follows me everywhere when I'm in Whiterun and it's really starting to get annoying. Has anyone else has this happen and if so have you found a way to get Hadvar to stop following you?

Try Killing him, if that doesn't work... then have a giant kill him?

I've tried that but sadly Hadvar won't/can't die. He just gets really pissed off and pummels me into Oblivion when I attack him or if I manage to attack him enough to lower his health all the way down he just sort of goes comatose until his health regenerates.

Damn. Because I really want to kill Hadvar. And was considering joining the Imperial Legion and

yep same happend to me.. its freaking annoying.. im on PC, isnt there a command to get rid of him like in oblivion? i think there was one that forces npc's to continue to do their thing? im not sure and i don't even know if it would work.

Yep same here, when I leave Whiterun out the main gate he spawns and starts walking down the road to idk where but when I go back in..he spawns