As a Halo fan since 2005, I could not recommend MCC enough. Although I do have very slight issues with it (lack of the original menus and credits, for example), having all of the classic Bungie games mostly preserved is a wonderful thing and are very much still worth playing ~20 years on. The run of the original trilogy was monumental in the gaming landscape in the 00s in terms of innovations and firsts, but at the same time, the stories, worldbuilding, and the fun still holds up for first time players despite the age of the games.

Multiplayer is a little brutal given that most people playing are veterans like me, but for a meager $10, it is well worth the price for the campaigns alone.