Hi there guys,
What is the best mouse and keyboard you ever used or still using for work?
I've bought Microsoft wireless mouse and keyboard but it sucks, keeps interfering with other wireless devices and works slow.
Looking to buy something better.
Apple keyboard and trackpad.
No mouse since I got trackpad, which is couple of years now.
Well, it's Apple thing, but should probably work if you use Windows as well.
Very subjective topic, but for the past 4 years, I didn't change a working system, even though it's quite basic:

Mouse:

I have it set to max DPI which makes it unusable for 95% of the people, since the cursor moves too fast 
I would recommend anyone who hasn't tried a different shape keyboard to give it a go. Your wrists will thank you.
Definitely, Bluetooth input devices suck, for the simple reason they operate on 2.4GHz band and easy to interfere with anything else wireless.
If the Microsoft set you have connects via bluetooth that should be the problem.
As for general and specific needs enything will work
.
Ps. US Embassy Security Policy suggests the use wired keyboard and mouse to avoid data breach 
Microsoft wired mouse and ergonomic keyboard here currently.
I don't like wireless mice and keyboards - sure, they slightly reduce the wire clutter on my desk, but they also run out of charge at inconvenient times.
CM Storm Mechanical Keyboard with Cherry MX Blue Switches
These keys click really loud and are annoying if you have anyone working next to you, but they make me feel like a hacker even if i'm just writing an email to my grandma.
Razer DeathAdder Chroma Mouse
like @manu_adefy I have it set to max dpi... it takes a couple days to get used to it, but now I can't go back.
Macbook pro keyboard and magic mouse (unless I am using the trackpad). Got tired of connecting external screens to my Macbook and just use it as it is.