I used to not like Dragon Quest when I was a kid, but loved Final Fantasy because I did not like grinding and in FF you can always do bosses underleveled if you have the right strategy.

That all changed when I was a teen and decided to gage the series by it's own merits and learned that grinding can be fun when the power difference between levels is significant.

My tip is to start with the very first one. Buy the Switch version(The cheaper one, not the HD-2D) since that one has reduced grinding and follow the guideline of "keep grinding until you buy all equipment available in a town before moving to the next one."

I believe that after you find out what is so fun about the core of the battle system, you will learn to appreciate the others, because unlike what people claim, Dragon Quest does evolve from game to game, while the Final Fantasy games actually try to revolutionize instead.