I just want to share some of my personal love for the Tales series.
For me, I love it because at its core its one of the few series on console that still sort of unapologetically uses the old conventions and is very traditional= direct leveling up from fighting monsters, set character classes and upgrade paths (yes, Xillia kind of introduced some customization here, but there was still an "auto-level", and pretty much set archtypes, and paths you were building your character to be). Towns with item shops, weapon/armor shops where you buy the gear that upgrades stats with money directly dropped from monsters or selling off your old crap, etc etc. I know with Tales, I"m getting traditional JPRG goodness, and not any of the experimental garbage that Square has been doing for a decade now.
Yes, the over-arching plots are sort of B movie compared to heyday Final Fantasy, but the characters themsleves are good to me, I enjoy the art, and I enjoy the often humorous tone and party banter within the skits. I like the fact that these games usually don't get too "heavy". In terms of plotline and difficulty.
Lastly- the series defining trait- the realtime battle system, is what keeps me in it. Probably the only JRPG series that doesn't get me eventually yelling, UGH, not another battle. I like the fast pace, the simplicity of the controls, yet all the little nuances, and the fact each character gives you a different experience if one gets stale.
Yes, I love this series, and its about the only automatic day one buy left me anymore in the JRPG world. Squaresoft in general got that distinction from me back in the SNES/PSX/Early PS2 days, but that long stopped somewhere betwen FF10-2 or FF12 when they really started screwing around, so I"m glad the Tales series really doesn't change much.