I finally finished Xcom on Classic, took me a while because Xcom is a long game and after I finished on normal I wanted to take a break of it.
Honestly, I like the setting, story and visuals of Xcom1 more, but Xcom2 has better gameplay, details and quality of life things, and I REALLY care about a game visuals. I find most aliens and weapons of Xcom2 a downgrade from the original.
If I had to pick one… tough call… I'd say Xcom2 because slowly advancing a map while on Overwatch gets old fast. I know Xcom2 can be cheesed but I take cheese over boredom. The game looks uglier for me in general BUT you can mod some stuff… but you can't mod a Thin Man one-shotting your Major Sniper in Xcom1.
Still, every time I see T2 armor in XCom 2, I shrug. I really miss the Mechs too…