Percussive:+1 to hit opponents with AC 16 or more. Otherwise, -1 to hit.
As I stated in my previous post: anti-armour weapon. Possibly anti-undead.
Sword:Swords are versatile killing tools typically used as side arms. They can be worn conveniently and don't provoke unwanted attention. Having a spear or flail slung over your shoulder suggests violence.
Axe:+1 damage, -1 to hit.
Axes are clumsy but inflict horrible wounds.
Polearm (spears, poleaxes, halberd etc.):+1 to hit vs. anyone not wielding a similarly quick and long weapon. Can be mixed with other categories. For example, a poleaxe would be a percussive polearm and have +2 to hit targets with 16 AC or more.
Lose all bonuses and get -1 to hit if in a place with very little space to move (if you can't stretch your arms out in every direction without touching a wall).
Polearms have been the default killing implement for as long as anyone can remember. And with good reason, as they're fast, long and versatile. However, carrying one down the street would be regarded in the same way as walking around with an M16: that you are crazy and dangerous.
Dagger:They have inherent bonuses because of their form and socially accepted status, inherent penalties because of their small size.
Flail:Ignore shields, on a natural 1 you twat yourself in the head.
Not the sanest of weapons, but they get a specific job done.