I know that the recommend version is usually one of the remakes, but I decided I wanted to get some perspective on the series's beginning in its original form so I went for the NES version. And it was rough, yeah. It was very rough.
Once I got past that initial confusion of the first hour or so (I struggled like hell to get to Level 2 because I didn't realize you had to manually equip armor since when you buy something the shopkeeper asks "Who do you want to take the armor?" so I assumed it auto-equipped to the character you responded with), though, I had a lot of fun. I really liked the magic system, the dungeons felt varied, I liked the classes, and I loved the spritework and music. I went in with low expectations, but I ended up regularly looking forward to what the next dungeon and boss would be like....