My problem is not about a reward.
My problem is that you literally saved the world and no NPC seems to care. Everybody still talk to you the same way, even the Jarl who helped you a few hours before. huge let down.
I was expecting a big change in the game after killing Alduin. I thought that I would become more know and I would be able to do more epic quests or something.
Of course they still are. What did you do? You killed one of the big dragons that attacked people but the others are still doing it so for most people, it seems you didn't do much. The reality is that you did a lot of HUGE things in the shadows.
Personal gain :
- you unlocked the last word for Call Storm, got the final Dragon Priest mask and you learned two powerful summon shouts
World benefit :
- Killing/banishing Alduin which if it wasn't done would only have led the dragon situation to worsen over time until the end of the world
- Stopped Alduin from eating the souls of the Nord heros that reached Sovngard. Now, that is a BIG one! (PS : I met Ulrick again there, he was rather kind considering all that happened before

)
- By removing Alduin, you paved the way for a pacifist Pathurnaax to reach the remaining dragons and maybe install some peace between them and the other races instead of a state of "let's eat them all"
Side note : a lot of actions you did have effect on Sovngard. I did the Bard first quest and I met the king in Sovngard that thanked be for putting to rest that bard that was after him

Or like I said, I met Ulric there etc...