Dreamcast is one of my all time favorite systems. The sheer amount of Capcom and SNK games on it made it a great system for fighters. Not to mention all the awesome shooters the system had like Gunbird 2, Cannonspike, Twinkle Star Sprites and more. It was the last big system to really support 2D games, and thats another reason I love it.
There were many other one of a kind games on the DC that I really liked, Seaman, Shenmue, Rez, Mars Matrix and more that I can't really think of off the top of my head lol.
The one downfall it had was that most of the best games were Japan only titles, and had to be imported..not really something I minded but still alot of people prolly did.
As for the controller, I never really had any qualms with it, it seemed to work well for me.