1. Thanks.
2. Thanks a lot.
3. Thank you so much.
4. Thanks a million!
5. Thanks for your help. / Thanks for helping me.
6. I really appreciate it.
7. I'm really grateful.
8. That's so kind of you.
9. I can't thank you enough. (for extremely important things)
10. I owe you one. (this means you want/need to do a favor for the other person in the future)

Fact
A 7-year study, which concluded in the summer of 2000, found that 33 U.S. deaths were caused by rottweilers, pit bulls were responsible for 27 deaths.      .. More >>