That's part of what I love about Dragon Quest, they are average jRPGs, but polished to perfection. They do take risks for the genre in many ways (I-V most obviously, but IX's single/multiplayer mix was pretty new too), but they don't define themselves that way, they shine for their finely crafted difficulty curves (Cave to Rhone withstanding) and balance... sure no game is perfect, but as I've gotten better and better at RPGs I find myself honing in on the best ways to do things, where in DQ almost any strategy is just as viable, and with the game adds new challenges so you can rethink your strategy, but without being obvious gimmicks either...
It makes you think efficiently too with the items thanks to bag sizes and money being fairly tight, so no battle feels like filler, you have to grind efficiently, or keep your MP up for the boss fight. Grinding in other jRPGs tends to feel like you'r just pressing the same thing over and over, but that doesn't really cut it in DQ, and even when it does you're still conscious of your resources. I like the feeling of finding a way to be incredibly over powered just as much as the next guy, but it's a fleeting feeling, and a game that challenges you and makes you think about every battle, even the grinding ones, holds my attention a lot longer.
And of course they're fun and charming and wonderful, which always helps.
Although I do have games I prefer over any DQ game, and even 3 RPGs (Final Fantasy 5, Breath of Fire: Dragon Quarter and the wRPG Arcanum), they're consistently great games, and it's my Favourite video-game franchise over-all.
Wait, what was the reason for this rant... oh, IX, yeah, that game was great, IV and V both beat it out for me, but it is a fantastic game, which I have spent many an hour on. Having so much content with the grottoes made it a blast that just went on and on, and was perfect for a handheld Dragon Quest. You could go on, bash some slimes, have fun, and stop. Or you could go practically endlessly go do something more substantial if you were on a longer journey, and you could even invite friends to play; it was frankly amazing!
Sadly we don't have much Joker 3 information, just that it's happening, the only statement so far is:
"Series creator Yuji Hori says Dragon Quest Monsters Joker 3 will have new systems, monsters, and connectivity functions. The game will have a new title logo designed by Akira Toriyama with the Nochora as the center."
They'll probably tell more soon though, they're just announcing things like wild at the moment so nothing's getting a huge ammount of spotlight.
As for LMS PS4, no news yet, but it seems unlikely. If DQH does well enough it might happen for DQXI (assuming of course it's for PS4, but it certainly seems likely at this point), but I wouldn't hold my breath personally.