Realilistically for Xbox 720

1.halo trilogy remake(too soon for halo 5)
2.fallout 4
3.alan wake 2
4.destiny
5.new ip in the sci-fi genre

Uncharted 4 for PS4; Alan Wake 2 for NeXtBox; Watchdogs for both.

Killzone 4.

Uncharted 4.

GT 6.

Medievil 3.

(Not really next gen) but port Diablo 3 onto PS4 and 720 with full online features.

Honestly most of the games I would want to see for 720 and PS4 I would prefer to come out at least a year or so into their respective console's life cycle so the developers have more time to get used to the new hardware and can get more out of it.

Most launch games over the past couple of generations have been pretty "meh" and don't hold up well compared to games released later that gen. Halo 1 on the Xbox and SSB Melee and Rogue Squadron 2 on the GC are the few exceptions. Go back and look at some of the games that the PS2 and the 360 launched with... they look terrible compared to games available at the end of their respective gens.

oh i forgot completely about last guardian lol they should give us some news about this game this E3.

they need to release at least one game that is popular which helps to sell the system

Hm Sony has a lot new IPs and Sequels in the making from their big studios.
Guerilla Games is making KZ4 and a completely NEW IP.
Naughty Dog is working on some stuff
Santa Monica Studios are working on a NEW IP
PD is probably working on Gran Turismo 6
QuanticDream just registered a few days ago their new project for the PS4.

Then there is probably a lot of Japanese Exclusive Support.
The PS4 is pretty much set.Maybe The Last Guardian and Versus13 moved to PS4 too who knows.

The nextbox hasn't much announced at the moment where i would be really interested.
There won't be a Lost Odyssey 2 cause Mistwalker won't work for them anymore.
Alan Wake 2 will be on PC too.Everything else i don't care for.

But what i would wish for when i buy in 6-7 years a cheap NextBox are games like Kameo and stuff(NOT Kinect stuff.A REAL Game)
Those games were what the 360 made interesting for me.

Nextbox: Besides unannounced new IP's I would like..

Destiny (Bungie4life)
Alan Wake 2
Shadow Complex 2
Ryse
Watch Dogs
Crackdown 3
Forza 5
Next Red Dead
Left4dead3

Anything else would be icing on the cake.

Exclusive:
Gran Turismo 6
Killzone 4
New IP
New IP
Wipeout Ps4

3rd party:
Watchdogs
Star Wars 1313

Then I want Uncharted 4 a few months after launch ;)

PS4 - Lineup:

Uncharted 4
Infamous 3 The Wrath of Cole
Crash Bandicoot
Watch Dogs

New IPs:

Platinum Games': Jesus Christ REVENGEANCE - Hack'n'Slash, Jesus comes down to earth and takes revenge on humanity for disrespecting him and god. Jesus will look like and act like Samuel L. Jackson.