Below is a list of fights I would like to see. I know some have already fought but i would like to see it happen again. Dana feel free to oblige.
Heavy Weight
Cain vs JDS
Cain vs Overeem
Fedor vs Mir
Barnett vs Lesnar
Lesnar vs Carwin 2
Light Heavy
Rua vs Machida
Griffin vs jackson
Hendo vs Rashad
Hendo vs Fedor
A Silva vs Fedor
Middle
Silva vs Chael 2
Maia vs Bisping
Marquart vs Vitor
Welter
GSP vs Fitch 2 (i know it will be a decision fest but I would like to see it)
Shields vs Diaz
Alves vs Penn
Condit vs everyone especially Diaz
Kos vs shields
Light
Edgar vs Pettis
Maynard vs Penn
feather
Florian vs Aldo
Nunes vs Mendez
Bantam
Cruz vs anyone
Faber to win again
I also know some will never happen.
Rua and A. Silva at LHW IMO 
The two fights on your list that stand out to me are Alves vs Penn and Lesnar vs Barnett. I would love to see both of those fights.
Lesnar vs Barnett would be interesting considering the Paulson connection and the fact that they're two fantastic wrestlers. Id' be rooting for Barnett.
Alves vs Penn. I like that, a lot. Let them bang.
Lesser bs Barnett interesting. Forrest vs rampage yawn leg kick fest again.
Shields vs Fitch
Chael vs Machida
Alves vs Diaz
Mitrione vs Carwin would be fun.
Alves vs Diaz would be great
Really good picks. I don't think that I'd be able to watch Fedor lose to Mir.
Lesnar-Carwin 2 needs to happen and Lesnar-Barnett would have epic MMA promos
Diaz condit. Penn Guillard. Munoz Stann. Ellenberger Fitch. JDS vs anyone.
damn good list Fight i want to see is Barbosa-Oliviera
HW - Dos Santos/Overeem
Antonio Silva/Lesnar
Fedor/Barnett
LHW - Mousasi/Rua
Rua/A. Silva
Rodolfo Vieira/Roger Gracie (not gonna happen)
MW - A. Silva/Souza
Akiyama/Santiago
Lombard/Belfort
WW - Hughes/Fitch
A. Johnson/Alves
Penn/Diaz
LW - Guilard/Alverez
Aoki/Penn
Penn/Aldo
Ttt
Cowboy vs Pettis
Machida vs a. silva would be insane