A year ago, I bought a Roomba 530. Roomba is a vacuum cleaner, but not a regular one, this one is a robot. In fact, Roomba is built by a company called iRobot.
I tend to avoid or automatize dumb and repetitive tasks, so I bought an automatic vacuum cleaner because I don't think a human should spend time to do that, time is precious and should be used for more interesting things (like watching TV or drinking a beer 😉).
There are a lot of robotic vacuum cleaners on the market but the price can be very different between the products, from €100 to more than €1000, so for €300 I think that Roomba 530 is a good choice.
Basically, Roomba moves in the room like a bug, going only once in some places and several time in some others. But when it detects more dirt in a place it spends more time on it.
Roomba 530 works on a lot of surfaces (tiled floor, wooden floor, carpet…), it detects walls, stairs, etc. But it still does not like some stuff, if the floor is not flat enough (~1 cm high bumps between rooms for example), or if an obstacle is too thin (chair legs). But the main problem is furniture with space about the height of Roomba. Roomba goes under the furniture and then may be stuck. Of course Roomba tries to get out of here, but it can moves your furniture a bit if it's not heavy enough.
So, if you have a lot of stuff laying around in your house, you may not buy one. If not, Roomba is very convenient. You still have to do some cleaning yourself but much less and less often.
The robotic cleaning market is quite small and some products are not sold for a long time. Roomba is still in stores, there are also other models (vacuum cleaners but also floor washers, etc.), some of the parts are easily replaceable (brush, battery…) and are still sold too.
For the geeks out there it seems that you even can reprogram it (never tried).
When Roomba does not detect thin objects, it hits them at full speed: