CANTONESE...I think they made a huge mistake making Mandarin an official language...I think Cantonese is easier to learn and also more fun to learn as you can watch (while learning) HK dramas and listen to Cantopop. There are a lot of "entertainment" stuff in Cantonese - HK movies, HK TV dramas, most good Chinese songs are in Cantonese - Cantopop has way more songs than Mandopop because of the monster-size entertainment industry of Hong Kong. Basically, everything fun can be enjoyed in Cantonese - people in the U.S., Canada, etc - most speak Cantonese. Sure, most people in China speak Mandarin but - they are still not yet developed and most you probably not interested in talking to. Learn Cantonese first, then Mandarin.