If you are ever in the Glasgow area of Scotland, then you should aim to checkout one of the three A1 toy stores in the area.
I visited both of their out of town shopping centre stores recently, the first at Braehead and the second at Silverburn. Both of these open until 9pm each weeknight and then between 6pm and 7pm at the weekends. Sadly I only had an evening free and was outside the opening times to visit their city centre store which closes at 6pm.
A1 is a brilliant mix of traditional toy store (think Smyths/Entertainer) with a big selection of collector based material. For collectors product can be split across the three stores, with the Parnie Street store in Glasgow City Centre holding the widest range as it also acts as their online base.
Across the two stores at Silverburn I found the latest (Smart Hulk) Marvel Legends wave, with older Legends going back through Captain Marvel and Spider-Man Far from Home. There were also figures from the Kingpin wave and even some older Mantis BAF figures.
I also found the more recent Wolverine & Hulk box set, Captain America and Motorbike and the Magneto, Quicksilver and Scarlet Witch Pack
Star Wars Black Series included the Battle Droid wave, with older figures on reduction. They also had stocks of both of the Archive waves to date. The stores also had loads of Hot Wheels ships - many of which I hadn't seen before in the UK.
For other brands we have a good selection of Marvel Select figures, McFarlane Fortnite, NECA and some higher end statues and prop replicas.