On subject. Mondblut had it right, female characters in CRPG should wear few or revealing clothes. Like chainmail bikinis. Or normal bikinis if modern setting.
IF going for heavy realistic approach, then the only stats women shouldn't be penalized compared to men probably are: dexterity (only if limited to actual dexterity and not agility), wisdom (if intelligence as stats exists) and charisma (but not charisma as in ability to lead people in combat, individual-only skill). But that isn't for every game though i wouldn't mind in modern or historical setting at all. Playing as a female should be more challenging there. You could give women some (serious) bonuses to interactions with men to compensate a bit.
If you don't care as much about realism and want the game to have similar opportunities for men and women then agility or intelligence and most things can be equal. Strength however even in non-realistic games shouldn't be equal, it is absurd. Give women an additional skill or bonus to compensate, say charisma counts as +2 for female doing any checks vs adult "compatible" males.
If you really want females as characters as strong or even stronger than males - in fantasy setting - make other races where women are stronger. Say a race where women are bigger, dominant and have a matriarchal society. THAT I wouldn't mind at all and could lead to something interesting. Instead we have races that are all, well, Americans/Europeans in 2000s only in different sizes and ear shapes. All equality, blah, blah. Real women and men ARE different, they have different "stats" in real life and have different social roles. But can't have this in a game so let's it be more boring and samey. Right? Why can't be choice between man and woman an actual choice mechanics-wise? Just like a race is? It would be both more sensible and gives even more varied choices when it comes to creating characters. Some crpgs tried to do it in the past (like Wizardry 6-7), some even still do (Knights of the Chalice 2) but it's mostly half-assed. One measly point more or less (in a 20 point scale), totals must be still equal, etc... Better than nothing, i suppose.