Base to base game cities skyline 1 or 2?

I dont really like buying dlcs because I think if I buy one I'll want to buy more if you get me. I have xbox game pass so money isn't really the matter but base to base game with no dlcs which is better? I've been shearching and searching for almost 2 hours now and some say cs2 some say cs1 so i don't know which to get now.