>>718574268
I'd say AC2 is worth it, yeah. It was the breakout hit for the series. AC1's main issue was repetitiveness, so the sequel amped up on the mission variety. There's also an upgradeable base and many more types of weapons. The story is a bit less philosophical and more of a revenge tale, though.
AC3 is set in the colonies and while that comes at the cost of making city parkour worse it adds wilderness maps with tree climbing and hunting. It also has a prototype of Black Flag's sailing and naval combat. Could be worth it though I'd advise against getting Remastered since it messes with the lighting.