Going from my old PSX, to the Dreamcast graphics was a HUGE leap, which I've never seen since. Got it just for NFL2K, but classic games like Crazy Taxi, Shenmue, NBA2K, Virtua Tennis, Phantasy Star Online, Alien Front Online, Seaman and Worms World Party made it worth having even for the short lifespan it had.
Being able to surf the web with a console was very cool, if limited compared to what a PC could do, but it always impressed people when I showed it to them.
The VMU (memory card) was PERFECT for calling football plays, my friends and I had binders with various formations and plays. Good times.
By far, the Dreamcast impressed me with what it could do, for the time, and though I loved having a hard drive in my Xbox when I moved on to that in early 2002, the DC will always have a special place in my gaming heart.