From the ones I've owned the Wii U is the best hands down.
I liked my Dreamcast but I never raved about it like some do. It had some good games but many feel very dated now. I normally find revisiting old dreamcast games quite disappointing. I can't bring myself to revisit soulreaver because I doubt it'll begin to live up to my memories.
The Mastersystem had a few very good games as did the mega drive. Mainly platformers but there were some real gems.
I never owned a PS3 but my xbox360 gathered dust as it almost directly competed (and lost) against my pc.