I know this is widely regarded as an unpopular opinion, but Head First is my favourite GF album.
I only really decided that recently, and while it's technically not as simple as saying X is better than Y when every album is amazing, Head First has my favourite aesthetic. Voicething and the album cover design says it all really. I love how colourful the music is. I love the heavy use of synths.
I do like the 80’s vibe quite a bit. The album ranks quite high on my list but my all time favorite is Felt Mountain. It was this album that got me into Goldfrapp when it got released and I still get goosebumps when I play it.