I like the Mystery Dungeon games better than the main series, to be honest. Level grinding is repetitive and boring, but what I like is that there's always something else to do. The storyline is very long and not overly intricate, and the boss battles are great.
The only gripe I have about the series as a whole is that there comes a point when, although there are still tasks to accomplish, nothing is remotely difficult. I have a Lv.100 Dialga with Time Tripper that I've pumped up with dozens of Vitamins, Ginsengs, Life Seeds, etc. etc. and a Time Shield; everything is unhacked. It's been months since I've come even close to fainting. Even Kecleon isn't a challenge anymore.
The only gripe I have about the series as a whole is that there comes a point when, although there are still tasks to accomplish, nothing is remotely difficult. I have a Lv.100 Dialga with Time Tripper that I've pumped up with dozens of Vitamins, Ginsengs, Life Seeds, etc. etc. and a Time Shield; everything is unhacked. It's been months since I've come even close to fainting. Even Kecleon isn't a challenge anymore.