Hi, I am looking for a type of glue that can stick the sensor (distance sensor HC SR04) to a piece of plastic. What type of glue is the best in this case?
Thank you
Hot glue.
A nut and bolt glue.
Duct tape - it has a light side and dark side and holds the universe together 
Seriously, for most things like what you are doing, hot glue is a great answer. The glue sticks come in a number of different types for various applications - some of that stuff is really tough.
I have used 5 minute epoxy successfully.
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Hot glue doesn't adhere well to some soft plastics that are loaded with plasticizers. I prefer answer #2.
I use low temp hot glue (you can seriously blister your fingers with the high temp). Small drops are usually adequately strong and generally easy to remove from smooth surfaces if needed.
Thanks y'all for the great Response. I did try epoxy and it worked!
e2738729:
Thanks y'all for the great Response. I did try epoxy and it worked!
Maybe.
We - or you - will see. 
There are a few plastics out there - namely polypropylene and polyethylene plastics - which are termed "low-energy surface" plastics, which means that the getting an adhesive to "wet" the surface (ie - stick to) is very difficult.
Both of these plastics are common household plastics - most plastic food containers and bags are made of the stuff (mainly because of mechanical properties - but also because food doesn't stick to the surface). Plastic cutting boards are another such common use.
There aren't many glues that can adequately adhere such plastics together.
One such glue (which many swear by) is 3M Scotch-Weld DP8005 - it is anything but cheap, though; 3 ounces (85 grams) will run about $40.00 USD.
There are probably less expensive options to try - the cheapest being (though it may take a lot of skill to execute properly, depending on the configuration) to melt the parts together (that is, a real mechanical weld bond).