OT-Half-Life 2 is a great…

[Suicide Junkie]

There was the whole pre-loading option, where the game downloaded itself over the Last few months.
If you bought it Online and did that, then now it just verifies your codes and decrypts the whole thing. (Very little internet activity, horrendous amounts of disk activity for an hour or two)

If you bought it B&M, you should have the CD(s) and not need to download very much (theoretically).