If it is my first time on a coaster, I love the front row. I really like not having anything obstructing my view on a new course. Then, like many others, I'll try the back row and see which I prefer overall. If time is of the essence....whichever row has the shortest line!
On a related side note, I had my own "Magical Moment" at Disney this summer...My friend and I went for the single rider line for Everest on our first ride out...I was really wanting to ride in the front, but it was July...so you understand the line situation! They called for me as the next single rider. There was a nice little pause, and he said "First Row". For further fun, they sat me with a really cute soccer player with a fantastic accent! Special thanks to the mouse on that one!!