For the main series, I've played the Dragon Warrior games 1-6, and have completed the Loto Trilogy, progressed fairly far in DQ V, am currently in chapter 2 of DQ IV, and have started DQ VI, but of all the games I've played, DW III will always be my favorite of the main series. I played Dragon Warrior I and II as a kid, but I was never able to play III or IV, which bugged me to no end, because I heard from a friend that you got to play as Erdrick in the third game finally, and that the story was gripping in the fact that you kept hearing about the exploits of you're father, Ortega.
*Spoile