Battlefront most likely, will wait on users impressions on here though, don't trust web reviews anymore.
Siege not sure. Loved the vegas series, and like the idea of this game, however, if this game only has 1 life per round / game modes, I'm out, especially if it runs on p2p and not region/ping locked servers.
COD, again not sure. Gave AW a miss (first miss in series since COD4), liked BO1 (even though that had issues on PS3) but wasn't keen on BO2. Also, if they have their hybrid network again then that will be a big turn off.
Halo, wouldn't mind trying but don't have an Xbox one. Would wait for users impressions first anyway after hearing how poorly MCC was implemented.