So I was reading a completely unrelated article about 90's SEGA ads in the UK, and it mentioned that a cinematographer called Geoff Boyle had worked on ads for a ton 'o companies, including Lego. Had a quick google, and it turns out that he's done quite a bit of work for TLG and documented it all on his website. Here's some of the highlights I could spot:
Adventurers Ad (the one with the kid becoming Johnny Thunder):
Technic Ad (the one with the wind tunnel):
2000's-ish Racers Ad (referred to as "Lego Racers 3" on his site for some reason?):
(guessing this one partly inspired/was inspired by Supersonic RC?)
There's bunch more on his site, so I'd definitely recommend having a look yourselves since some of it is actually really interesting. Also here's a link to that article about the UK SEGA ads he did since it's actually quite a nice read too.