The PlayStation 2 is well-known for having some of the best collections on it and this one is definitely one of the best. The Mega Man Anniversary Collection comes with Mega Man, Mega Man 2, Mega Man 3, Mega Man 4, Mega Man 5, Mega Man 6, Mega Man 7, Mega Man 8, Mega Man: The Power Battles, and Mega Man 2: The Power Fighters.
All of which are presented with their original graphics as well as new options which you can turn on or off such as added difficulty settings, an option to use the original 8-bit soundtrack or a remixed CD quality soundtrack (which was previously used in the Japan-exclusive "Rockman: Complete Works" and sound really nice, a weapon switch button which was later used in Mega Man 9 & 10, and a save feature! No longer do you need to write down passwords as the game will save your current game progress to your memory card after you complete a stage.
This version also removes all lag from the games, especially noticeable in Mega Man 3 which is infamous for lagging on the NES. The games overall feel much smoother now and refined, even though nothing about them as changed. I do have to warn you though on the GameCube version the jump and shoot buttons are reversed - meaning that A shoots and B jumps. It's not a deal breaker however if you can get this on the PS2 or Xbox I'd suggest it.
The reason I would suggest getting this version over the upcoming Mega Man Legacy Collection on PS4, Xbox One, Steam, and Nintendo 3DS is because that version is more expensive and comes with less features than this one even though this one is a decade older.
OVERALL: I think this is one of the best collections on the market. It has so much content and anyone who is looking to get into Mega Man or relive their childhood should pick up this version because it is truly the definitive version.