What do you think are the top 10 toughest Xbox Live Arcade game to 100% and why?

First off, let me say this, I am not counting any games that have not been 100%ed, I am only talking about ones that at least someone somewhere has 100% complete all the achievements for that game, if no one has completed all the achievements then I am not counting that game. Examples of games I am not counting:

Astroids/Astroids Deluxe (no one has Platinum acheviement), Battlezone (no one has General achievement), Warlords (no one has Earl achievement, its glitched), Smash T.V. (no one has the last achievement on there [50g], its glitched). I will not count those because until someone gets the final achievement on them then they are deemed impossible.

Heres my list: and in order of most difficult 1st: #1 Rush n' Attack, #2 Joust, #3 Space Girrafe, #4 Robotron 2084, #5 Tron, #6 Super Contra, #7 Discs of Tron, #8 Geometry Wars, #9 Tempest, #10 Xevious.

That is my list, I have completed some fo the ones on this list: #7 + #10 but I do consider them to be among the top 10 toughest. Also I have not even one of the ones on this list: #4 but due to reputation I must add it.

So whats your list and do you agree with mine?