Dragon Quest games are not very plot heavy. The plots tend to be 'save the world from evil."
What I tend to say is that Final Fantasy games are about the characters, Dragon Quest games are about the towns and places you visit. The characters certainly matter (especially in certain games, like V or VIII) but the focus of the games is the places you visit and their trials and tribulations.
What they tend to be is just fun. They're certainly generic in that Dragon Quest is the template that all JRPGs are born from, but they focus on the sense of excitement and adventure instead of diving up their own asses. Even the most serious of the Dragon Quest games is still a lighthearted adventure story. They're certainly a bit samey, especially compared to the Final Fantasy franchise and its huge variety, but they're dependable.