megatron, chris johnson, and stafford are shoo-ins IMO
You really cant go wrong with your last pick. Because its a dynasty league, I lean towards Green. Marshall and Green could easily have very similar seasons this year. If you think youre going to need a RB or they are heavily valued in this league, go with Jackson. If you think you can find a suitable RB as your 2nd back, go with Green.
It was close for me between Green and Brandon Marshall but look at what Green did in his rookie season with no training camp. The kid is the next big thing and in a dynasty you should get 10 years of production out of him barring a crazy injury.
Add in the fact that Marshall is a head case and more risky.