Wacom has been industry standard for many years, for very good reasons. They're the best.
The Wacom Intuos line is what you'll find across almost all studios, not just game studios but any professional office with an art focus. You'll find a mix of Intuos Pros and older Intuos 5 and sometimes 4's. Some pay for the Cintiq but many artists dislike them. Same with the latest Wacom One. Merging the screen onto the tablet works for some, but to many feels like a gimmick, not quite right, especially the ergonomics of looking down that can hurt your neck or lifting your arms up to a display. The newest models have no hotkeys and no touch ring, that's an issue if you've constantly got your pen in hand.
If you're confident enough in getting old drivers, an old model like an Intuos 4 or a 2013-era Pro would work just fine and they are generally quite cheap if you shop around or hunt for bargains. They're especially cheap and plentiful from bankruptcy sales, liquidation shops, or surplus stores if you can find them and your timing is right, often just a couple bucks for a set of 4 or 5. Be careful to get the matching pen, since the hardware needs to match.