GQ tobaccos generally are the best priced, but can go out-of-stock easily because of the popularity.
3 other people I have ordered off of and generally, are good service (all-be-it slightly more expensive).
cgarsltd.co.uk
www.thebackyshop.co.uk
mysmokingshop.co.uk
But I have also ordered from outside the UK from the States for tobaccos that you cannot obtail in UK and 4noggins.com hasn't steered me wrong yet! Even if you do get caught for VAT it will still work out about the sameish price as UK.
TIP: DO NOT ORDER TO THE UK FROM THE EU!!!!! The tobacco laws from within the EU are absolutely s**t!! I have had a package stopped before and confiscated- without the request to pay tax!!! I had to write to customs pleading my case, pay loads in fines, VAT, duty and fees and ended up working out over £80.00!!! (not including the initial cost of tobacco).
HTH