Rainbows End is a great standalone novel. And Marooned in Realtime is like old school Asimov with great new ideas... you can skip its prequel Peace War.
I found Peace War very interesting on two axis. First, the exploration of human intelligence augmentation and second the commoditazation of nuclear weapons impact on politics and "state" ie when the state no longer has a monopoly on violence. I personally did not enjoy Rainbows End much, whatever that's worth.