I think Scherzo is their bestseller, which @IDontHateRainbows has mentioned liking. I like Poirier d’un Soir (think I must like scents with a rum note, funnily enough I do also like drinking it 😆). I thought Myrica Muse was nice too. I think Tea Tonique is another popular one!
Re. sample sites - I agree about Fragrance Samples UK and Small Aromas, both have been great for me, as have Scented Samples and The Perfume Sampler. Definitely use TrustPilot as I think there are some scammy ones out there!