-Armored Core
It pretty much all went to shit from Armored Core: Nexus onward, where the focus of the game became gimmick after gimmick.
AC4 did redeem the series somewhat, but I don't own a PS3 or 360, so I didn't get into it.
-Kingdom Hearts
Starting with KH2...yeah. The one everyone fucking loved.
And really, it wasn't the core gameplay (which was...odd in how it was balanced) but rather, the plot..I can't even properly describe it, but the first game's tone was set up perfectly from start to finish.
The second game didn't reach nearly the same level for me.
-Final Fantasy Tactics
FFTA ended this one for me...I liked the political atmosphere of Ivalice, and the seriousness of the story (without it becoming too dry or boring). So naturally, Squeenix had to churn out a fairly tepid "kiddy-version" because it was on the GBA. Don't get me wrong; FFTA isn't terrible. It's pretty decent for gameplay, but the story was just STUPID (oh you go Marche. You go and act like a condescending twat to your crippled brother).
What makes this sting even more is what happened to Ivalice AFTER FFTA: FF12.
Ugh..
-"Mana" series.
Yeah, I'm still picking on Squeenix. But they really did use the Mana franchise as a "shitty game dumping ground" for a few titles after Legend of Mana before just burying it forever.
HerbertTheHamster said:
X-com
anything after tftd was terrible, with the exception of apocalypse which was decent.
Terror From the Deep is just a reskin of XCOM 1...but with all the player's weapons nerfed into shittiness.
Oh, and Lobstermen. Fuck Lobstermen. Fuck them with a Thermal Shock Lance.
I found Apocalypse to be better than most of XCOM 1, actually.
Psionics was far less broken, and the environments were pretty damned cool (albeit, cartoon-y).