Snape
For once, Snape's presence at a funeral wasn't solely due to hollow social obligation.
He'd approved of Theo as a student, and as a man he'd respected him - Theo had been that rarest of beings, a genuinely worthy colleague in the risky and demanding business of war. Above and beyond everything else, Snape had felt a uniquely personal empathy with Theo: the man's position in this war - a deep cover agent in Riddle's inner circle - matched his own position in the last war entirely too closely. He'd felt the responsibility of being Theo's contact keenly, and had been genuinely relieved when they'd managed to successfully retrieve the man and his family.
And now, this: the man had been killed, when Snape had been more hopeful of his chances of survival than most. The news of his death had been a bitterly unpleasant surprise.
So he attended, with none of the carefully hidden boredom or resentment that almost always accompanied him to funerals.
For once, Snape really was there to pay his respects.