Male or Female?
There is no "better" sex. It depends on what you want, your preferences. A pet should always be fixed, but even then there are a few differences. Neutered males are more laid back, mellow, and easy going in most situations. Spayed females have opinions, a little more demanding (aren’t all females) and are more active.
A few facts and differences between the sexes.
If you are looking for a pet, an animal that will bond with you and love attention, then your piggy must be fixed. Pigs also stay smaller if fixed. Intact boars chomp their teeth and create frothy foam that has a foul odor. Boars will "mark" their territory with this foam and with a pungent liquid produced by their "boy parts". Boar's tusks grow very thick and long. Boars do not bond well with people unless they are looking to hump someone. Boars are also prone to testicular cancer. Neutered males do none of this. They are calmer and bond very well with people.
Intact females are almost worse. Left intact they start their heat cycle at about twelve weeks old. They cycle every 21 days and the heat last 5 to 7 days. They go through a very strong hormonal change and yes suffer from and lash out because of it. It is very similar to PMS. During this time they will jump on anything and anyone in an effort to breed. Keep this in mind if you have small animals or children. Intact gilts and sows will also whine for hours and call to try and find a boar. The incidence of life threatening uterine tumors and infections are very high in intact females. They are also prone to mammary cancer. Another problem is that during their heat, which lasts 5 to 7 days, they "forget" or don't care about their potty training. Having the female spayed eliminates these problems.