No deposit bonuses come in two main flavors: free spins and bonus cash. Neither is universally better. They suit different kinds of players.
Free spins: simple but restricted
Free spins are tied to one slot (or a small set) chosen by the casino, at a fixed bet size. You can't save them, change the stake, or use them elsewhere. What they offer is simplicity: click spin, and anything you win converts to bonus funds. If you enjoy slots anyway, spins are effectively pure upside.
Bonus cash: flexible but watch the weighting
Bonus cash (or a 'free chip') can usually be spent on any eligible game at any stake within limits. That flexibility is powerful. You can play lower-variance games to grind through wagering, but game weighting rules often reduce table-game contributions to 10% or less, quietly inflating the real requirement.
The verdict
Slot players should generally prefer free spins with a low wagering multiplier and a high cashout cap. Players who like tables or want control over stake sizes should look for bonus cash with fair game weighting. Either way, the wagering requirement and max cashout, not the headline number, decide whether the offer is worth claiming.