Finally... I've got all 120 stars and then all 120 again... and then the last one! 121! It's over!
Seriously, I can't think of many games where I've been happy to play through the whole bloody thing straight after finishing it the first time.
If you need more detail, after getting all 120 stars, you have to play through the whole thing again but as Luigi. Even the hard annoying levels. And all you really get at the end is... **Spoiler Deleted** and the letter above. But I feel it was worthwhile and that I'm a better person for it.
And I'm looking forward to moving onto something else. I'll miss it though.