Well let's see... I'm kind of fuzzy on exactly when they merged, but three games that I have played since then are:
KH2: No where near as good as the first, but I was able to get through it, if only so I could see how the story played out. The original was fresh when it came out, but the second felt like a weak rehash. The so called improvements over the first actually made the gameplay worse in my opinion. And I can never forgive what they did to Atlantica (my ears are still bleeding from that...). The inclusion of Jack Sparrow helps a great deal, but I still fell that KH would have been better served with a second disc to finish off the story instead of a sequel.
DQ 8: Ah, Dragon Quest, the last of the "Old School" RPGs... The Americanization this game went through during its trek accross the Pacific annoyed me, but nothing too big was changed, so I just delt with it (and turned the "Voice" volume to zero). Still, for my money, the series peaked with no. 5. 7 was so-so, with 8 being better, but not as good as 4, the best installment to make the states in my opinion. I'm hearing some bad rumors about 9 that I hope aren't true...
Grandia III: Note that SE only published this game, this and all other Grandias are the work of Game Arts. Now then, this is going to sound harsh but... for those of you who loved Grandia I and/or II and are dying to play III... don't. You're in for a huge let down. The graphics rock and the battle system is good, but about halfway through, the game literally collapses in on itself. This game would be considered short if were on a single CD (it's on 2 DVDs). Characters dissapear into thin air, never to be heard from again (ever!), plot points are left dissapointingly unresolved, and the difficulty increases exponentially near the end. For what it's worth the original is still the best (and the Locker Room scene pwns the Ghost Ship Pipe scene).
As far as Final Fantasy goes...never got into it. I tried to play 4, 6 and 7, but was never able to get into any of them. The only FF game that I ever finished was FF USA (mystic quest), but no one I know (including myself) considers that a true FF.
The Mana series... I'm in the minority here, but I believe that 2 is superior to 3. The gameplay was less clunky in my opinion. I also believe that the much hyped "Triangular Story System" or whatever it's called is a crock. Any combination of characters that you pick yields the exact same progression of events until the end, when depending on who you picked as your first character, one of the three main villians suddenly and without warning just happen to defeat the other two... Beyond the various back stories of the heros, there is no character development to speak of. There is no chemistry (good or bad) at all between your party members, reguardless of which ones you choose. On a side note, I am perplexed by the rumors that SD 2 is really half the game it was supposed to be. I can only imagine what stuff they had to cut out because the planned SNES Disk attachment got canned...