Since the question was best graphical game, I'm going to say Quake1. At least for me, out of all the graphical games to come out, that one has held the top. Albeit, if you take multiplayer out of the question, I'd have to change my answer to possibly Deus Ex or something else.
Now, since most people are answering for best graphics of all time. That is a tough question, do we assume within the time period of release or do we take time out of the equation. For best engine, I'd answer Doom3, but best graphics as in beauty and artistic stance, that would be rough. Naturally, Farcry was very pretty, but there've been other games such as Prince of Persia, that also have an awesome look. Honestly, I'd have to round up a few games and replay them to answer what game looks the best. I tend to forget when a game looks really good unless I've screenshotted it.
Oh and here would be my console choices:
PS2: Devil May Cry 3
GC: Metroid Prime