Input Needed: Dinosaur Fight Tournament

With every second that passes, we get closer and closer to the official release of Jurassic Park 4. As we near that date, interest builds not only for the series, but for dinosaurs in general. Sadly, since the release date isn't looking to be any time soon (late 2014, perhaps?), we need something to occupy us while we wait. As a crazy 3 am sleep deprived idea(I'm taking a nap after I write this), I came up with the idea for a tournament... A tournament to determine what the most dominant dinosaurs of all time were. I haven't quite worked out all the details yet, but I'll tell you what I have: The dinosaurs are split in to 5 classes: small, medium, large, and very large. For example; in the small class would be dinosaurs like Bambiraptor, Troodon, Velociraptor, Pachycephalosaurus, and Coelophysis. Medium would include species such as Suchomimus, Albertosaurus, Yutyrannus, Utahraptor, and Toujiangosaurus. Large would feature titans like Giganotosaurus, Tyrannotitan, Tyrannosaurus Rex, Allosaurus, Spinosaurus, Triceratops, and Stegosaurus. The very large class will be exclusive to sauropods and titanosaurs. However, the very large will fight against medium to large sized carnivores, usually as an individual or perhaps two that have to fight the predators in packs. Another evener of odds is the rule that if smalls like Velociraptors take on Utahraptors, they will have a bigger pack. Maybe 6 on three? Some dinosaurs will be excluded, like Protoceratops and Archaeopteryx, since they can't really fight that well. I should also warn you ahead of time that there PROBABLY won't be a Spino vs. Rex battle for two reasons: it's been done to death and it would cause controversy if one beat the other. There may occasionally be non-dinosaurs in the challenges, like Sarcosuchus and maybe Dimetrodon or something. This will be 100% unbiased. Depending on how successful the series is, I may go on to make an underwater edition, then perhaps an ice age edition. What dinosaurs do you want to see face off? Any suggestions as to rules? Should landscape, bystanders, and weather be factors?