My top three favorite NES games are hard to pin down, but off the top of my head, I'd have to go with Dragon Warrior IV, River City Ransom, and The Guardian Legend.
Dragon Warrior IV was one of the biggest games produced for the NES. In fact, it couldn't fit on a standard cart, so Enix had to add extra hardware into each copy to expand the memory beyond what the system's theoretical limitations were. The storyline was epic, the way it broke down into chapters which each focused on a different main character or set of characters was ground-breaking, and the remake/upgrade they did on the DS was phenomenal. It's easily my favorite 8-bit RPG of all time.
River City Ransom is Double Dragon but with two-player simultaneous play and a ridiculous sense of humor. Run through the streets of River City with your best friend, beat up the various gang members you find, and then steal their pocket change to go buy food at the mall. I've crashed through this game dozens of times over the years, and it never gets old.
The Guardian Legend is what you get if you crossed Gradius with The Legend of Zelda. It's part vertically-scrolling shooter, and part top-down action adventure, all done with an awesome space theme, and a brilliant soundtrack. It starts off simple, but gets hard as hell towards the end, with enemies all over the screen and your own massive arsenal of special weapons to fight them with. Just an incredible game that deserves to be remade, but due to nobody actually knowing who the hell owns the rights to it thanks to any number of studio closures, buy-outs, and bankruptcies over the years, we're never likely to see it re-released on a Virtual Console or updated/remade/sequalized for modern-day systems.
Awesome topic, my man! Thanks for the opportunity to blather on about the NES. :)
I'm just happy that there are a few people on here that were alive when that system was released. Prior to the NES the only sort of RPG I had in my life was Dungeons and Dragons - like with the books, dice, and pencils. Some would argue this was a more healthy way to role-play but it certainly wasn't cheaper! Those hardcover guide books were easily 30-50$ each.
I have to admit i have never heard of Guardian Legend. I'm gonna look that one up now.