I am not going to deny the fact that Halo is, to a very very many lot of people, a fantastic game. This said, however, I must take the typical anti Halo position, and call it generally overrated. Its accolades don't need to be listed, because anyone who knows anything about games already knows them. What I can tell you is that its hugely repetitive, and is really just a repetitive FPS that survives on a hype machine.
Shenmue, however...oh, wonderful Shenmue. An unappreciated masterpiece of the adventure genre, Shenmue not only masters its genre, it defines it. It produced the greatest console graphics yet to be seen, and it created the most real and interactive world seen until that point. Some criticize the game for being slow, but I say that's a load of bullshit, and why not take your time through the masterpiece that is Shenmue. It popularized the QTE concept that is present in a huge variety of games today, it created wonderful combat, and it tells one of the most brilliant video game stories ever. It is a forgotten classic, and it outclasses Halo in nearly every definition.