I dunno about consoles but I have imported loads of games from both Japan and the US and its very rare I have been hit with customs charges.

I know dcultrapro bought his Jag CD from the US as it worked out much cheaper.

Have a look at this mate.

http://customs.hmrc.gov.uk/channelsPort ... _CL_000014

I was hoping someone would simplify it 

The general rule is that they open it if the decalared value is over £50 to see what it actually is and then charge you accordingly.

If the person marks it as a gift on the customs note though they won't touch it 

That said though I have had plenty of stuff slip through the net.

I tend to get all my stuff marked as a gift,

There is a guy in Japan I buy loads of Saturn games from and his prices are not only insanely cheap but so is the shipping and sometimes I get the games in less than a week! 

That is fast shipping for overseas!