Oblivion:
Where to start? My eyes bleed just thinking. Guardhouse had been traduced "casa delle guardie", Shock spells are traduced "Colpo", that basically means hit (in italian, a with shock/chock we mean something traumatic), "Crusader's graves" are traduced "Ciccioli del Crociato" in google (a cicciolo is... mmm... a bit of flash/meat, and maybe a pornstar),
Fallout 3/NV:
Less issues, but most of the time the voices dont tell what the dialog should (for the reasons that you can see in Oblivion).
I have to say they did a kinda good job on german version of Jagged Alliance 2. Sure much original intended puns can only be understood in english but especially Ivan Dolvich is still hilarious with some of his comments (good thing they left his russian parts of the speech files)..
I've just started playing Jagged Alliance 2, and i dont want to know what they would have done to a such beatiful game translating it (Dragune, instead of Dragunov, Italians can do much worser(Dragunov sounds like Dragon, that in italian is said Drago/Dragone. Dragune is a contraption(? not sure is the right word) of Dragone (Dragon that sounds like Dragunov)). For me it has some of the best dialogs ever, and with the fantastic voice acting of the original, hearing them ruined by translator could have leaded me to madness.
"That could have been bad, but i got me some kickass karma"
"I hate every bug on the way. They we're many"
"I forget, i forget to forget!"