Mine like the gummy type Nylabones.. they are a little softer and more pliable so it's not as hard on their teeth but it's still really strong. I also love this product from Merrick called Texas Toast. It's rawhide but it's shaped into a thick toast shaped thing. Mine love them and they never have chewed off big chunks of it like normal rawhides. I still suggest watching them while they are chewing them though.
Pizzle sticks are nasty but the dogs love chewing them too.