This font is Arial, or am I wrong? Need to know the exact font, please!

Helvetica Neue  Suggested by dfcrux 

makes me think about this shirt

thaaaaaaaanks! that's the one! but I can't find anywhere I can download it for free! :(

no, you have to pay for it, sorry

You would get it "for free" if you had a Mac.

yeah "for free", because the Mac is like 4x the price of a regular computer...
so yeah, they can "offer" you the Helvetica
=)

I have a mac! So what should I do? :O

look if it's installed.
if not, click on the link dfcrux gave you.