My first choice - Apple direct. I always get Applecare+ with my phones or macs. For piece of mind more than anything else. They have always been good with service etc. on occasion you do need to push and prove your point, but on the whole they are good. Once had a MacBook that needed a logic board replacement 2 weeks before the 3 year Applecare was due to expire! I can tell you, was glad I had Applecare for that!
Anything MacBook/Mac or especially high value, I always purchase from Apple direct.
Second choice - John Lewis. I see someone above has had a bad previous experience - not the case with me. I tend to buy smaller items, like Airpods etc from John Lewis, as they come with a free extended guarantee. I have twice had to send airpods back and both times they were just replaced - no issues at all.
I avoid Amazon at all costs with anything Apple.
I once purchased Apple Airpods from Amazon - these came from Amazon direct, not a third party seller. I specifically made sure they were Amazon supplied.
Used them as normal. After around 18 months I upgraded my iPhone and my Airpods would no longer connect to my new phone.
Went into Apple, who took a close look and couldn't work it out. They sad the airpods had been replaced an unusually high number of times. I said I had them since new and never replaced them before?! They said the left airpod was last replaced by 'Susan' a month ago. I said no, I don't know any Susan and I've had these Airpods for 18 months - even had the original Amazon invoice to show them!
Turned out the Airpods were fake!!! The guy at Apple was even shocked at how good of a clone they were. It seems the serial number had been cloned across a large number of units, hence the reason for the unusually high return rate on this serial. Basically I had a genuine serial on fake Airpods!
I complained to Amazon, who said they would take the Airpods back and have them repaired!!!
I said no, I paid for new Apple Airpods, not fakes.
In the end they refunded them, and I repurchased from John Lewis, and they've been perfect.
Granted, a MacBook is unlikely to be a clone - but considering Amazon themselves were unknowingly supplying people with illegal clone products was enough to put me off. Hence I would never buy anything of great value from Amazon again, especially anything Apple.