FF7AC was mostly good voicewise, but they wrecked Cait Sith by giving him an idiotic accent, and Rachael Leigh Cook brought down the whole movie with her unnatural and stilted performance.
On the other hand, Quinton Flynn was spectacular, the new child actors in AC:Complete were good, and everybody else was competent.
It's true that there are a ton of terrible English dubs of things. People often see the terrible ones, and then project their bad feelings about them to ALL dubs. Like, just because Sailor Moon's dub was genuinely awful, they ignore the really good ones like Cowboy Bebop, or the pretty good ones like Dragon Ball Z (which had more problems with English script rather than acting).
Kudistos Megistos, I hope you're not including MGS1 when you say the MGS series. About half of the voice acting in that game was phenomenal, but a lot of it (namely Naomi and Mei Ling with their terrible fake accents) was plain atrocious.
Of course, the reason things get bad dubs is because they don't have Andrea Romano acting as casting director.
For an example of a remake being worse than the original, look no further than FFIV DS. Maybe it's the fact that they really slowed down the game, maybe it's that the 3D graphics actually look WORSE than the original 2D graphics, or maybe it's the horribly acted cutscenes, but there's virtually nothing better about it than the original.