One thing that must be taken in consideration here is that Aggramar isn't at his full power right now. Were he a complete Titan? I am certain he'd be able to kill all of these opponents. However, we are facing a fraction of what Aggramar's power actually is, as his orignal body was broke by Sargeras thousands upon thousands of years ago.
I believe Deathwing would be taken out but it would be a troublesome fight regardless.
I believe Kil'jaeden actually would have the most trouble against him as Kil'jaeden is more adept at deceiving his opponents. There is no doubt in my mind that he is a very worthy and powerful foe but I think that Kil'jaeden would lose to Evil Aggramar. Kil'jaeden while was also powered up by Sargeras I don't think he would have the best experience in one on one combat - if Kil'jaeden had his pawns on the chess board this would be different.
I believe Archimonde would prove the most challenging to Aggramar both in size, strength and intellect. For once I don't think he would be as arrogant as he is with mortals I think he would go all out and not underestimate Aggramar even once. This one would be the closest of all the fights here and I do think Archimonde would win out all of these opponents. Archimonde was also empowered by Sargeras so I think that would be a bolster to his power.
Lastly the Lich King, while the Lich King is the most fearsome, bad ass, and most creative story in World of Warcraft. I do not think he would last long against Aggramar, even if Aggramar is at a fraction of his power he would squish the Lich King like a bug and all of his scourgelings.
Pairing such bosses is a difficult to decipher who would win. But that is how I would see it. I think it also depends on location and the scenario itself.