I have seen 1/2 inch long neon electric metallic green beetles here.
They are rose chafers and live in old fruit trees, therefore becoming rarer as people [legalised vandals!] grub up old trees.

Stag beetles are also quite common here (Surrey/Hampshire/Berkshire).

A more frequent problem these days (though perhaps not technically a 'bug') is the 'false widow spider', which is spreading with the popularity of wooden decking - apparently this one can bite and is poisonous, though not fatal ... so far. I realise that you folks in other parts of the world have much nastier spiders, but in southern England we are not used to such dangers.