My wife plays LEGO games. I am forced to complete them.

Right now, we're playing LEGO Indiana Jones 2.

We have three achievements left.

1.) Finish Area 51 in less than five minutes - this will require two players and probably put a strain on our marriage.

2.) Get all the achievements for 100%, see below.

3.) Play through all the levels in "quick play" mode. Sounds simple, until you do the quick calculations - 3 movies in the original trilogy = 15 levels per movie, plus Crystal Skull, broken into 3 parts = 15 levels per part... 6 times 15 equals... 90 levels?!? Which we've already played through. At least once. Dammit.

We've got LEGO completionitis on this end.

I play them to completion as well.  But this time with Lego Indy 2, I just could not finish those last three.  I refused, I was so burned out that I put the game down and havent been back since.  Believe me I feel your pain with the Area 51 Achievement.  I tried several times with friends and even my wife and yes to your assertion it did almost ruin those relationships.  Best of luck to you.