Which Cities Skylines Should I Play?

I used to play the original Cities Skylines several years ago, but eventually quit to go play other similar stuff. Recently, I have been itching for a good city building game, and considering getting back in. I am on PC with Game Pass, so I can play either of the Cities Skylines games with my subscription.

I generally just want to play the game that has the most up front content, polish, and the one that overall feels better to play for someone coming back to the series after close to 5 years.

Should I play 1 or 2? It might be important to note that I do not own any DLC for either game and don't plan on buying any.