UK hobbyists, where do you source your parts ?
For small orders I generally go to Rapid Electronics, they are quick as their name suggests.
Generally I try and avoid Digikey as they have quite a high shipping fee. Farnell/CPC seem ok and quite often I use Mouser.
What suppliers do you use ? 
An excellent UK supplier is HobbyTronics who offer a wide range of products, very good service and clear pricing. They are also very responsive to technical queries. Goods are dispatched promptly and well packed
CPC for hobby users have a very good range.
Many of the UK based suppliers of Chinese made components on Ebay are good, their feedback rating is a very good indicator as are their sales volume numbers. Some Ebay sellers charge ridiculous mark ups even given they will probably incur import (VAT) charges on goods coming into the UK. These are best avoided.
I just use Farnell as I am confident they supply genuine parts. Ebay parts are ok for experimenting but anything I want confidence in comes from Farnell.
One of the hobby shops in England I like is BitsBox. Worth checking out.
Don’t forget RS components too.Very reliable.
The only thing to watch out for is their minimum order quantities for some things. Sometimes you may only want 1x part, but they have pre-packaged them in x5 or x10 quantities, so this can be a problem.
Farnell follows this practice too, but to a much lesser extent.