For me yu-gi-oh cards! Back in its prime oh my god the fun times.
And when I say start over I mean alllll the waaay back to the first series with starter decks and non of this newage shit.
Do you mean as in, if I could forget all about that thing and do it again like it was all new for me?
In that case, GIMME BACK MY FIRST TIME PLAYTHROUGHS OF THE MONKEY ISLAND GAMES!
My favourite game series of all time, but they never had any replay value since the puzzles are so memorable *sigh* (altho I've played through Curse plenty of times just for the laughs).
id take Cross Country/track a little more seriously than I did soccer. Soccer was more a hobby, XC/track coulda gotten me to a bigger, more expensive college for less (or free) if i took it more serious and gotten more scholarship opportunities than i did that i could actually take.
Hmm... either pokemon games, or Mabinogi. both are pretty quaint.
Probably Pokemon games because I LOVE them but you will never experience that same feeling you got when you first played them D: (back with red and blue).