The Family Way
To put it bluntly, no!
The purpose of becoming the Evil Overlord is so that you can do what you want. Having a spouse severely limits what you can do from your want to do list. They are always wanting you to spend time with them, instead of torturing that hot thing in your dungeon. And they are constantly giving you the disapproving look when you kill someone who needed some killing. If at all possible, do not get married!
If you have already married prior to your decision to become the Evil Overlord, avoid the kid scene at all costs! They demand all your time, money, and anything else they can get their grubby little hands on. Once they become of age, they will take one of two paths. Either they will hate you and all that you stand for, trying to kill you and end your rule. Or they will lust after your power, and kill you so that they can take over. Either way, you are screwed. It is best to just avoid the kids.
Sadly, there are those of you who already have kids. Your road is going to be a tough one! Not only do you have all the planning, scheming, and our chores relating to world domination to do, but you also need to take care of the family. You need to spend time with the kids so that they will love you and not want to kill you. You have to teach them so that they are not naïve and can be fooled by some smooth talking rebel. If you have kids, you probably have a spouse, who also has needs. If you ignore any one of them, I guarantee they will become the catalyst to bringing you down.
It is better all around just to avoid the whole mess. Oh sure, that means you will be pretty lonely as the Evil Overlord. But so what! That is why the torture rooms were invented. And game rooms. And home theaters. And books. A small sacrifice to make to shore up the possible weak points in your regime. Deal with the loneliness.
Besides, when are you ever going to have the time to woo any potential date? By the time you take over, any potential date will have at least one of the following problems. Either they are after you for your power and will be wanting to kill you shortly, or there is something completely wrong in their head! Either way, both are good enough reasons to run the other direction!
Suck… I am screwed. I’m married, have a new kid, plan on more… to be truly Evil, I suppose I could kill my family? Is that kosher?
No no no! There is an added bonus to having kids (do not need to elaborate on a spouse, you KNOW those benefits.) Kids can be taught to defend their overlord parent. They can become some of your most loyal henchmen. But always keep in close contact with them. You do not want the other side influencing them in ANY way!