Holtby told UEFA.com: "He's physically and mentally very strong as well and he just loves the game, that's what makes him so good. He keeps scoring for us week in week out, he's a fantastic player.
"I've played with some very good players, such as Raul and Huntelaar but I think Gareth is one of the best. He's one of the top three players I've played with."
Bale has been in excellent form of late and has scored six goals in his last four games for Spurs in all competitions.