The first Final Fantasy is amazing. I've never been one to depend on graphics, so even playing it for the first time after I'd played the tenth in the series, it is still addictive. There isn't quite as detailed a story as any of the later games, but when you consider it was one of the first console RPG's, it's not bad compared to much of what else was around at the time.
The second Final Fantasy has a far more in depth story. It effectively shames the first game as far as story goes. It is also much more character based than FFI.
The gameplay for Final Fantasy I is similar to most of the other Final Fantasy titles. It differs about as much as any title does from any other, with the exception of FFII.
Final Fantasy II differs greatly from other titles in the series. Not in the battle sequences themselves, but in the way you level up. If you are accustomed to normal Final Fantasy games, I personally recommend that you read some information on how stats level up before getting into the game.
Graphics and sound are actually pretty awesome for the time in both games. Nothing much for todays standards, but any hardcore gamer worth his salt doesn't depend on graphics or sound quality, as long as the gameplay and story are good enough. In Final Fantasy Origins, that's exactly the way it is.
Individually, I'd probably rate Final Fantasy I at about a 9.2. Final Fantasy II would get a 9.4. But since they are both packaged together in Final Fantasy Origins, I'll give them a bit of an extra bonus for value, and make it a 9.7.