Is there a skin product that you would 100% repurchase if it never gets discontinued?

Today, while I was organizing my vanity, I came across an empty cream bottle that I've already used up three times. Haha. Looking at it, I suddenly became really curious about what other members' must-have items are in their vanities, so I'm leaving a question!! Don't you all have at least one skincare item that you stock up on whenever there's a sale and are 100% willing to repurchase? Haha

I have sensitive, oily skin, so even a little bit of oiliness causes breakouts, and if I use something too light, my skin gets dry and my makeup comes off. ㅠㅠ That's why I've been a skincare nomad for a really long time, and recently, one moisture ampoule that I've settled on has become my life-long must-have. I buy a whole box whenever it's on sale in case it's discontinued. Could you please share a list of your must-have skincare products that you 100% would repurchase?

Expensive department store brands are great, but I also love cost-effective products from road shops or drugstores!! Especially these days, when my skin is dry and dull, if there's a magical product that makes my complexion brighter the next morning, I really want to know about it ㅠㅠ Regardless of the type of cream, toner, or ampoule, please recommend a 100% repurchase-worthy skin care product among basic products.

If you could leave a comment with the product name and a brief reason why you liked it so much, you'd be truly blessed. ㅎㅎ I'm going to collect all the comments about skin products with 100% repurchase intent, which contain your honest testimonials, so I can go raid Olive Young this weekend!! Please give me some sales fun~~