IMO, it was one of the best 90s cartoons. The animation wasn't mind-blowing or anything, but it was as good as it needed to be. The writing was usually pretty great, and the jokes landed most of the time. And, IMO, it had a really good cast of supporting characters. Roger is an all-time great cartoon villain/archrival. Patti was a love interest with some real depth. Skeeter was a pretty good sidekick. The superhero alter-egos were generally pretty fun.
Doug himself is a very relatable, everykid type of character. Obviously inspired somewhat by Charlie Brown, but he's a fairly original take on that archetype.