Due to my interest in following tech news, people often ask me for recommendations when they need to buy a new phone, laptop, or other tech.
Smartphones:
Android: I'd consider a Fairphone if you have the budget for it. Although it does not offer the best specs at its price point, you are buying a phone that is repairable, has long term support, and is made as ethically as possible. If the Fairphone is not your cup of tea, I'd go for a Google Pixel, they're great phones and benefit from long term support too.
iPhone: I personally like refurbished phones as they are much cheaper and will generally still receive udpates for years. If you're not getting a new battery with your refurbished phone, I'd suggest to check the amount of battery cycles (ask if not specified). You want less than 300 cyles ideally so that you get a battery that lasts. For context, under 300 is considered low and above 600 is high.