do i have a good voice?

http://www.youtube.com/watch?v=UNehNMJ5wxAfeature=channel_video_title

i want an honest opinion i dont think i do and anytime i show my
friends one of my videos they laugh and say i suck at singing but they
really are just ball busters who will say something sucks when its not
all that bad. so can someone tell me how it is because i would love to
go down to the beach or in the back and just be able to sing and play
and have confidence and know that people are enjoying it. thank you