LiChess analysis is free and better. I don't know what the Chess.com paid analysis is like, but on LiChess you can just run Stockfish on your games and analyze different lines as you like. On Chess.com you have way less flexibility (at least with the free option).

LiChess also provides post-game analyse features, allowing Stockfish to determine alternative lines, and also learn from your own mistakes.

I never used chess.com, so I cannot really compare. I'm an avid user of the linked site, and use it play both with friends and users around the world. So far it's been a great experience, and I still have lots to discover : chess studies, tournaments and alternate game modes.

I've used both, lichess' free is better than chess.com's premium.