I thought the original MegaMan X for SNES was one of the best in the series. However I think the following games progressively got worse as they went on. MegaMan X6 (the last X game on PS1) was pretty mudane, and not very memorable. X7 took the sub-series into 3D, and man did it stink.
The game had a weird 2D to 3D gimmick going for it. Except it just made the game harder, not more detailed.
They also introduced a new character Axl. Never play as him.
You could also play as Zero, and that's who I usually did pick. Even his saber skills were not enough to save this game from being put back into the drop box at Blockbuster.