I just got Fozzie a small, heavy stainless steel bowl with thick rubber on the bottom, and Fozzie has yet to topple it over. He likes to splash in his water and tip it, and he has done well with it. You might've tried a stainless steel no-skid bowl, though?

Lola uses a hard plastic cat fountain, with no problems. We clean out the whole system at least 2x per day, and I always check it for knicks.