I wish I could play all of those sexy PS3 exclusives on the comfort of my PC, like God of War 3, Metal Gear 4, the Ratchet & Clank series, the Uncharted series, Killzone 2, the Resistance series and LittleBigPlanet. Not to mention the "trilogies / collections" that have come out lately, like the Sly Cooper Collection (never played them when I had a PS2), the God of War Collection and the upcoming ICO / Shadow of The Colossus Collection.
I wish I had a PS3...
The only exclusives for the 360 (and consoles in general) I wish I could play on my PC would be Red Dead Redemption, Alan Wake, Shadow Complex, Limbo, Splosion Man, Enslaved, Bayonetta and Vanquish.
As for Wii games goes, I only wish the Wii had higher resolutions and better online structure, like a propper VOIP without clumsy peripherials and draconian friend codes. Other than that, I'm fine playing Wii games on their respective console.