Well... Halo Reach in my opinion (yes MY OPINION that I MADE), not refering what ANYONE ELSE has ever said or implied. I would be hard pressed to make the logical leap from Halo 3 to Halo Reach... every other halo it seemed if they have overlayed the series with not only gameplay improvements but technical advancements as well- and perhaps it may only be the environmental design or Art but I felt that Reach didn't quiet meet up with the technical or graphical standards that you usually see going from title A to title B.
However Reach did improve the physics of the game, every projectile depending on mass and velocity can prove lethal if it directly hits you... and this in of itself is an achievement as far as coding and scripting is concerned. The vehicles have been significantly improved because of this, in Halo 3 you were limited in what you can do with your vehicle- but in Reach you can spend a lot of time scaling up objects, doing flips, and anything you can imagine doing- it's too bad they didn't add a racing playlist in MM.
The campaign was designed around playing in a competitive setting either by yourself or with a partner... the missions in MM tend to be an Arms race to see who can score the most points, and since each part of the mission is scripted it can get hectic when everyone charges into a particular enemy to claim a kill for more points. As far as being viscereal, the campaign is a loss... the story and setting were bad, and how it was presented was bad.