Before the last battle, there's a fairly interesting filler arc based around the team going to Earth.
After they save Snow, the anime goes off on it's own, Loco and the catgirl become regular characters, and Phantom's ending is a lot different. Then during the King arc, pretty much everyone dies apart from Ed, Ginta, Jack and Bell, including ex-Chess members such as Ian. Everyone but Snow gets revived though, and when Ginta and his dad goes back home, he and Koyuki become a couple
Also around episode 81, the anime gets the animation team that eventually stayed on for Hayate, which means that the fanservice levels grow, a lot. (Including gay stuff such as Phantom caressing Alivs' naked stomach in a field of roses)