Amazing that in 26 months Wii U gave me about 5 exclusive games I can say are must owns and defined the system, while the Dreamcast offered up a good few dozen games that I'd easily also name as must own exclusives. Granted I'm a SEGA fan, but the Dreamcast really didn't offer up many returning IPs from the SMS to Saturn era, it was mostly new IPs (Crazy Taxi, Shenmue, JSR, SC5, Seaman) with the returning IPs being greatly changed from their originals (PSO going MMO, Sonic Adventure going 3D). Not to mention the third party titles, especially Capcom's output. And just about every genre had at least 2-3 AAA titles.
As mentioned, I'm not a huge fan of Nintendo's franchises outside of Mario, but even then all I've ignored so far on Wii U was Pikmin 3, the Zelda remake (well, I own it, but it was bundled with the system), and Smash Bros. I'm racking my brain for longtime Nintendo IPs I've ignored, but none come to mind.
Point is, despite an early death, the Dreamcast felt worth it. The Wii U, meanwhile, has yet to feel worth it.