What size fuse for your pc and appliances..

I was just fixing up a new monitor on my desk and it got me thinking.

Whenever I am moving around my computer or other stuff all I do is take the nearest "kettle lead" and plug it into my appliance.. But different appliances have different fuse requirements..

Here is the way mine are currently fused..

Monitors - 5A
Computer - 10A

There isn't much about this online but I saw a quick eBay guide that says pc's should use a 5A fuse or older pc's could get away with a 3A...Anything higher and you run the risk of damage (or fire!) in he event of a power surge.

Im sure I picked the 10A for my pc at random..Should I change it for a 5A, it has a 650W PSU(corsair).

I'd consider it too be a fairly serious issue as you could get a surge anytime..As for a surge protector im sure I should have one of them but have never used one before(obviously never lost equipment to a power surge either!)

Do you guys ever think about this or just choose leads at random?