I'd really recommend WXY Candles. They are plant based (soy wax) and reasonably priced IMO. The aesthetics of the candle is on point too; minimalist and sleek (definitely something you'd genuinely want to 'recycle' as a pen holder or whatever once the candle runs out). I bought my one on their website, but I think Next and Debenhams sell them too.
This is the one I'm burning now: https://www.wxycandles.com/the-shop/p/candle-bed
It's a cosy scent, kind of musky but with a touch of vanilla. I bought myself the reed diffuser version of 'bed' because I like the scent so much.