I had a Dreamcast and that was a pretty good console it's just that the PS2 came out shortly afterwards and everybody went out and got that. The selection of games for the Dreamcast was also limited, but there were also some classics (such as Crazy Taxi and Shenmue). Also piracy was a big problem for the Dreamcast. Sega didn't really put any copy protection on the games - it was a multi-session layout with the game data stored in the high density area of the disc that couldn't be read by PC drives. However people began to copy the data onto PCs by using the broadband adapter and copying over a network or using a serial cable. Once the CD images were made and put on the Internet, anyone could download and burn the image and it would boot up as normal. This made the (limited collection of) games not sell as well and Sega had to stop producing it.
Sinclair C5 is a good one, when I read this a picture popped into my mind of the Amstrad phone with a screen ( I'm fairly sure it was Amstrad), can't remember what it was called and never knew anyone that had one. The idea was you were meant to be able to call someone else who had the same phone and see them as you spoke to them, don't know if you needed a special phone line or anything I haven't seen them for years so I presume they went the way of the DoDo.
Anybody remember Video2000 video cassettes? This was the first VCR my parents bought in 1984 and they kept until 1991 when it packed up and they bought a VHS. The tapes were double sided and you got about 4 hours on each side. Dad always used to say the picture quality was better than VHS and when you did freeze frame or did the rewind and fast forward, the picture never broke up or gave those lines that you get on VHS. This was probably because the video head was upright and not tilted, but even so, I don't know of anyone else who had a Video2000 machine. click here that's similar to the Pye machine that we had and click here that's one of the tapes.
I still wake up at night screaming, remembering how I used to try and service those machines. There was one model, Lowe Opta (I think ) which had a tape loading mechanism worked by a length of cord and a spring. AAGGGHHHHH !!!!!!!
Good clear tone, total lack of quality and if you go round a corner you lose the signal!
p.s. I regard a test of quality as being able to tell one violinist from another. I'm not over worried about losses at the bottom because my big base cones (15") are now a bit soggy now but I really cannot see how any system that has such a narrow bandwidth that it cannot tell the difference between a Violin and a Viola; a retrograde step.