Final Fantasy 7, Cloud looking up and shinra hq, with the big sword and spiky hair, I think is a classic image. The culmination of the Midgar section of that game is in that building, the cover is simple but sweet. I think another part of this discussion should be the best end disc screens where I think Final Fantasy VII wins hands down with its beautifully rendered pictures of the main characters, barret with marlene in Aeris Garden, Yuffie looking over Wutai, etc. Final Fantasy 8's were sort of weird and I don't remember Final Fantasy 9's. I also think Final Fantasy VII had the best "sleep" song too (can you tell it's my favorite game.)