Some Pokemon, like Magnemite, never have genders. Some, like Gallade, are always male. That is listed on the Bulbapedia list that you read.
However, most Pokemon have a 50% - 50% ratio of male to female. Some Pokemon, like Starters, have only a 1 in 8 chance of being female. Same with Luvdisc - it's rare to find a male one. Generally, though, you'll find Pokemon with a 50-50 chance. Not every Pokemon has a specific gender.