Intellivision, currently my sister keeps it at hers.
Maybe in my attic there's still a Polistil console, with four built-in pong-like games, not replaceable.

It was like this:



http://schiacciapensieripolistil.blogspot.it/2014/08/video-games-polistil-vg2.html

IIRC mine was dark grey and a different colour, not light blue, maybe it was an unbranded clone.

oldest console i own are, Atari 2600, NES & Genesis.

The PS2, since I've sold my older consoles like the SNES and the PSX!

NES ....still rocking it today on my 60" tv

Atari 2600, not only that but it's either the original model (1977) or the 1978 model. Apparently the only difference between those two models is there weight so I haven't bothered to actually figure out which it is. Wood Paneling ftw.

I have. NES x 2. Game Boy, SNES, N64, GameCube, Wii x 2, Xbox360, Original 3ds, Wii U and an Xbox1.

I have video game systems from all eight generations.  But for proof of one from the first generation, here is my boxed Nintendo Color TV-Game 15, from 1977. 

Atari VCS CX2600A, it's the 4 switch model they came out with in 1980 I believe. A friend of mine has the Darth Vader one and it looks awesome.

The second oldest would be my Intellivision.

snes

NES, SNES, N64, PS1, PS2, PS3 and Wii.

We also have a dusty Atari 2600 on display.