Welcome! ( i’ve moved this to projects so you can get individualized responses based on your own needs and preferences.)
First we’ll need to know whether you are in the US or the UK, as the device selection is different.
There’s no one “best” answer as different people have different needs and budget. For example, if you need really sensitive humidity sensing, such as for storing guitars or monitoring certain kinds of plants, then most of the available home automation devices just aren’t sensitive enough. But the Kumo wireless tag sensors from Cao gadgets are much more precise, so some community members get those. However, they require also using their own bridge device, so it can get expensive. Still, if you need that level of precision, it’s a good choice. These also have excellent weather proofing and long range.
Many open/close sensors and some motion sensors have temperature readings built-in, and that can be a good multipurpose device, although the sensitivity may not be great, and you’ll only get reporting maybe every 15 minutes or so. But typically good enough for running HVAC equipment for Home comfort.
And of course the multi sensors like The Fibaro and the Aeotec multis have temperature and humidity readings, but again not always that sensitive. Still, this may save on your overall budget if you also need a motion sensor in the same area.
The Everspring ST814 is a good intermediate device. Not as precise as the wireless tags, but more precise than your typical multisensor. It also has its own display screen, which again can be useful when you are monitoring a specific microclimate, as you can see what’s going on when you’re in the area. And it usually costs less then the multi sensors which have built in motion detection as well. We have several community members using it for things like monitoring a wine cooler, a cheesecave, etc.
So it would help if we knew your particular requirements as far as using these devices. Is it just for general home comfort? Or is there something specific that you are monitoring?