#1 Don't throw "10/10" So casually... 10/10 signifies perfection. Meaning that there could be nothing extra put into a game to improve it. Suikoden DS has lots of room for improvement. If a majority of people are giving it a 9, then You should be happy that a great hand held game got a great score...

#2 Final Fantasy 4 doesn't quite count as "Turn Based" when there is an Active Time Battle gauge involved.

#3 In Language isn't a barrier, I say check out Kimi no Yuusha. Prefer English? Check out Rhapsody: A Musical Adventure.  The keyword of this topic is "Turn Based" and the classic turn based genre is very dated, so you wont find many titles on DS.