I've lost count of the amount of times I've replayed Grim Fandango, Monkey Island and Broken Sword. 'A lot' doesn't even begin to cover it...
It was only the last time I played GF that I realised you could go down onto the deck of the SS Lola, right after you land at Puerto Zapato. I felt pretty stupid that I'd played the game so much and only just found it out.