That would most probably be It's My Life... The chorus pretty much describes the way I live my life right now. I always try to make the most of it and think I should do certain things now before it might be too late

It's my life
It's now or never
I ain't gonna live forever
I just want to live while I'm alive
My heart is like an open highway
Like Frankie said I did it my way
I just wanna live while I'm alive, it's my life

-- Sara