everything about ps3's launch. Ridiculous price. Horrible gamelineup for god knows how long. PSN was awful initially. Sony banking on bluray exploding like cd and dvd did. Losing so so much exclusive 3rd party support.
360. RROD fiasco completely ruined the console's imagine, and it would not recover till the complete slim redesign of the console. Focusing way too much on Japan which was a lost cause. It wasted so much money buying up exclusive rights to a bunch of jrpgs. It would have benefited a lot more getting exclusives that catered to Europeans and Americans.
Wii, While you could argue the system could have benefited from being more powerful, I feel nintendo would have done horrible had they gone that route. Being slightly more powerful is pointless. For it to be meaningful the wii would have to jump to 360/PS3 level performance so developers could port games to the wii. Had it done that it would have been significantly more expensive, and quite possibly allow the ps2 to continue being the "casual audience's" console choice. And the wii would have still recieved the worst 3rd party support because it's control scheme was so different than the other consoles.
I personally think the wii did everything about as perfect as possible. It took a hit in third party support and longetivity in order to be the cheapest console. Its control scheme cost it a lot of third party support as well, but allowed it to captivate a huge new audience.
