Asda George have a small selection of toys inc Lego with upto 30% Off PLUS they have an offer of save 20% when you spend £50 on Toys, the offer includes over 2200 items inc their fab range of wooden toys + the ones that are already discounted.
The upto 30% section isn't huge but with the extra discount there are some real bargains to be found, ie LEGO Technic CLAAS XERION 5000 TRAC VC (42054) now £71.98, LEGO Technic - Bucket Wheel Excavator - 42055 now£119.98, LEGO Angry Birds - King Pig's Castle - 75826 now £46.38 which are all cheaper by quite a margin.
If nothing takes your fancy in that selection then 20% off £50 Spend at this time of year is brill, I love their Wooden Toy range & with the discount it makes the George Home Wooden Dolls House and Large Furniture Set (£70 if bought separately) just £52.
Other products that seem really great value include LEGO Star Wars - Millennium Falcon - 75105 for £76 + Sportspower 10 ft Quad Lok Trampoline with Easi Store Enclosure and Flash Zone for £78.15 Delivered.
Will pop some links in comments