Any one of these songs:
http://www.youtube.com/watch?v=K2hMQRlU_S4
That video lists some of the catchiest songs from 2008 and 2009, including:
1) Matt & Kim - "Daylight"
2) Noah and the Whale - "5 Years Time"
3) Mayer Hawthorne - "Just Ain't Gonna Work Out"
4) Free Energy - "Dream City"
5) Passion Pit - "Sleepyhead"
6) The Heavy - "Colleen"
7) The Knux - "Cappuccino"
8) The Very Best feat. Ezra Koenig - "Warm Heart of Africa"
9) Coconut Records - "Any Fun"
10) Beast - "Mr. Hurricane"
11) Crash Kings - "Mountain Man"
12) Discovery - "So Insane"
13) Crystal Castles - "Courtship Dating"
www.youtube.com