First, my apologies to Second Spitter for misreading your earlier post.
I agree that OPS is thought by many to be the best baseball hitting stat, although many in the Sabre community would put Runs Created, Wins Above Replacent, or park-adjusted WAR ahead of it. Ruth does very well in those categories generally, but I don't think you can equate Bradman's BA vs all other cricketers to Ruth BA or OPS vs all other baseball players (if that's what you're suggesting--please correct me if I'm wrong). Ruth was never considered the best 'pure hitter' in baseball (most would choose Ty Cobb or Ted Williams for that). He was the premier power hitter, the first to hit 'home runs' on a regular basis, and making them a key component (and fan favorite) in baseball.
Perhaps there's no way to compare Ruth to any cricketer, or Bradman to any baseball player for that matter, because with Ruth I'm asking not about someone as good, but someone as famous, well-liked, and well-known as Ruth. But baseball is predominantly an American game (not ignoring it's great popularity in Japan, parts of Latin America, and a few other countries), while cricket has a major following in quite a few countries, as Adders pointed out. So ideas like 'most popular' all time, or 'most liked' or 'most respected' (though I doubt that one would apply to Ruth, or to Grace either, for that matter), are going to vary tremendously from country to country.
If this is anywhere near accurate, then perhaps cricket has no Babe Ruth, just as baseball has no Don Bradman nor W. G. Grace.