I'm with Darkslide.
Every art has it's strengths and weaknesses. However, if you want to train to learn how to "handle yourself" (which I will separate from the concept of "self-defense") then you need to look to MMA as a guideline - since here you train against resisting opponents in a wide variety of scenarios.
You learn striking and kicking, plus an awareness of someone trying to take you to the ground. If you DO end up on the ground - you know the preferred position is to be on top, in control. If you are on the bottom - you have trained to get out of there while protecting yourself.
Is it PERFECT in a "street" scenario? No - not when multiple opponents and weapons comes into play. But in all honesty - not very much will truly help you here. If you are set upon by 3 or 4 blokes, the best you can hope for is to escape intact. Again, though - MMA training will help if you have a good jab.
YouTube - Turkish Badass Fights Off Multiple Attackers
As for anti-weapons training well again, it is mostly a farce. You are going to get shot or cut. IMO the best you can get here is a false sense of security.
So what to train for MMA? Well - BJJ, muay-thai, boxing, judo, wrestling are the main ones - as well as actual MMA classes, of course.. Notice a theme? - yes, all training against fully-resisting opponents.
Aikido? Well - there are numerous benefits of aikido. It is easier on the body then some of the more "full-contact" styles above. Your reflexes, agility and ability to maintain distance in a confrontation will improve. You learn to fall and roll with confidence. So for those that do not want the "roughness" then Aikido is a good alternative although frankly - the "roughness" is what you will encounter in a confrontation anyway.