What games would give me a thrill of scaling and defeating large obstacles? Like mountains and monsters.
Why would you want to scale a monster? If it is big enough to scale what makes you think of even getting close to it? It could kill you by breathing on you. Wouldn't it be better to get away from it and hit it with something real powerful from far away? Like a nuke?
Shadow of the Colossus seems obvious.
There's some big bosses in the first Castlevania: Lords of Shadow (I know 'cause I got stuck on the first one).
God of War series also.
Also, I guess a lot of the bosses in the Souls games could qualify?