Ermygerd I might be wrong but these are the ones I think can be seen;
I'm not sure but Sea Guardian Duo/Legendary Beasts/Regigigas might be able to be seen ingame. Not sure about these.
Anyway. You can see like Latios, Latias with Benga... and ones like Cresselia/Hetran... BATTLE TOWER OF COURSE. >:D. And subway. can't forget that. :3