This was a tough decision, I honestly love Tamaki and Hikaru equally. But if I had to ship one of them with Haruhi it would be Hikaru.
He can be self centered and Rude somtimes. But when it comes down to it he really doesn't mean it. He would do what it takes to help his friends.
Haruhi understands the Hitachian twins better than anyone. Because of this Hikaru develops a soft spot for her, as does Kaoru, but with Hikaru it is different. Hikaru puts up more of a distance with people than Kaoru does. Without Kaoru Hikaru is lost. But Haruhi changed that.
This is my favorite scene. Hikaru had to put away his selfishness and help Haruhi in her time of need. He sheds his usual care free mischievous attitude, and reveals the real him that was to afraid to get close to people.
Let's be honest. They would make a cute couple. He's obviously in love with her and she understands him better than anyone. Tamaki can have the place of Haruhi 's dad. I Ship her with Hikaru@hikaymm