usually I prefer the boy toy, but sometimes I like the girl toy. If I didn't want to fight with my kids over the toy I would just get the boy one.

Are there other differences? (Are the boxes different, for example?) Haven't been to a McD's in ages, so I've no idea.

Like when they say, "Boy or girl," just say, "Well what are the toys?" Then see which one he would like. I don't think you should feel weird about it all, it's the societal exaggeration of male aggression and female display/nurturing characteristics that's weird.

I apologize for not putting this is in clear bigger context. Most of the "boy's" toys seem to be weapons or some kind of action figure which so seem to exaggerate male aggression. I am trying to pay attention more to what "girl's" toys they are offering. I know that most stores that sell toys do tend to characterize toys this way too. Going to McDonald's makes me wonder why a fast food restaurant is so into gendering toys though, but maybe they are just following that trend.
Many people say that boys and girls and different and that they naturally prefer certain toys. I feel like companies and society as a whole tries so hard to push it onto them. If it were so natural, why push it at all?

I wouldn't recommend eating there myself. Food poisoning more than once for me.

If they insist on offering two different toys, they could offer it as a choice rather than asking the gender of the child. Just because they choose to gender all toys does not mean that individual girls or boys might not prefer the other toy.
I have never been a big McDonald's fan. When we lived in a bigger city for a year, I ate there twice when it was only two blocks from where we lived. My son, a picky eater, seems to love the Mcnuggets and regularly asks to go there. We also have limited options for meals that we don't make at home since we live in a small town. We haven't got food poisoning yet but there are some food quality problems there as well as failure to give us the right food most of the time (we always check now).

That is how long (or, I'm sure, longer) they have phrased the question that way.

My daughter always cringed during the dual-toy promotions, since she knew what was coming the minute they asked the question:

Is it for a girl or a boy?
Please tell me what the toys are
Is it for a girl or a boy?
You don't need to know the gender of my child in order for my child to have a meal with a toy in it. What are the toys?

Sometimes it took several iterations before they would describe the toys, rather than asking for the gender of my child.

Then we would drive around to the window, and they would smugly point out that my girl daughter had requested the girl toy.

I went round and round with corporate (at the national level) - who insisted that their workers are trained to describe the toy rather than ask the gender of the child. But I got a look at the keys when I actually went inside one time, and the keys are labeled "boy" and "girl."

They'd do the Barbie/Hot Wheels promotion once or twice a year, but otherwise, they never asked that question.

Nowadays, they NEVER only have one toy. It is always a "girl" toy or a "boy" toy. Backlash? I think so!

When we were growing up. We are in our early thirties.
I do wonder if this is part of a culture that wants to encourage more definite masculine and feminine roles.

Some things have definitely changed for the worse in this area since we were growing up.

the toys seems so much cooler back them

We don't go to McD's much anymore, but the toys were usually a tie-in to the latest movie. Gendered toys as the default means more than one merchandising contract at a time, and possibly a premium charge to anyone wanting to promote their film exclusively (i.e., a month with only one toy instead of two). I always asked my daughter to look at the toys and choose which type she wanted. There's only so much pink plastic she can stomach, so we often got the "boy" toys.

You could use it as a chance to teach him that McDonald's is wrong for placing genders on their toys. Tell him he can play with whatever toy he wants. Once it is his, it is a "boy's" toy.