Sailing the Blue Skies since 2001.
Resident Evil 4 (GC, PS2, Wii)
I have finished the Wii version of the game, and for the most part, it should be considered the definitive version. The Wiimote control scheme is mostly well mapped onto the controller (bringing up the inventory with "-" and using "+" to pick up things in the inventory are the only issues I had), and aiming Leon's gun really feels good after taking some time to getting used to how it works. The action commands are now more predictable to perform (shaking the remote or jamming A and B quickly are your options), but are also a bit more enjoyable to do, too. Separate Ways is an excellent addition to the game, and Ada's mission, while much shorter, manages to be about as fun as Leon's, so that's a big plus. My recent playthrough even bumped RE4 up a peg on my list, so I can easily say that the Wii version is the best of the three. Highly recommended, especially since it's now $20 at some retail outlets.
Original Notes:
This game is the pinnacle of last generation's console titles. Capcom has outdone themselves with RE4 on just about every level that they could have. By reworking the RE scheme into a new and much better camera system that places it behind the character, changing the enemies from brainless zombies to infested villagers, zealots and commandos who have actual AI, who weave, block their face, gang up on you, duck, arm themselves with sickles, scythes, crossbows, rocket launchers, chain saws, pitchforks, axes, tasers, dynamite, hammers and gatling guns, and can actually communicate with each other (in Spanish, no less), adding in a merchant who upgrades your weaponry, giving you control over two characters at certain points, adding in "dodge" and "action" commands to increase the tension, superb boss fights and excellent ambiance...everything about RE4 is amazing. This game has been drifting in and out of my dreams, reminding me of the gameplay bliss I have been experiencing for the last few months. The amazing graphics, voice work (despite the hokey script), sounds, level design and controls round out the best game in the last few years. I must recommend that you give this a try ASAP.
I'd been tackling the PS2 RE4 in a race against my wife (who was playing the GC rev), and I've noticed a few key differences. First, the models took a major blow in the rendering department. The faces of the enemies are noticeably downgraded, and Leon and Ashley's hair are more like large glued chunks compared to the slick GC models. Some background elements have also taken a hit (examine the woman hanging on a pitchfork at the beginning, or the dumpster loaded with bodies in the second section of the village, for example). The enemies also seem a tad smarter, dodging a bit more frequently than I remember them doing before. The ground is more prone to absorbing bodies that have fallen into it, with the village's main square going towards the second section and the house where you fight with Luis being prime examples. Lastly, Leon's flashlight is more noticeable (and is in a horrible place...). However, despite the downgrade in visuals, there's nothing wrong with the core gameplay, and that's what really counts.