If I had to take one, and only one, i would go for Ving Tsun. MY rationale is as follows. For one Ving Tsun can be as effective as Krav Maga in combat ......with the difference being that Krav Maga is more immediately effective than Ving Tsun. This means that if you and your (imaginary) twin start training at the same time, and your twin starts Krav Maga and you opt for Ving Tsun, that your twin will be able to beat your behind almost immediately. However Ving Tsun is still one of the best martial arts out there (even though Bruce Lee created Jeet Kune Do by removing Ving Tsun's traditional aspects and adding principles from other martial systems). Ving Tsun can be extremely effective in self defense, and in close quarters combat a well trained exponent almost has no equal. After all, if my Ving Tsun history does me any justice, it was created by a Chinese nun. The good thing about fighting systems created by females is that they use an economy of motion, have to be extremely effective, and do not need a person to be able to do flips.
The thing about Krav Maga is that it is extremely simple and straight forward, and thus quite effective since all the time is spent on defence. Ving Tsun has three forms, and obviously a lot of time spent on sticky hands and the wooden dummy (Jeet kune do has sticky hands and the wooden dummy, but did away with the forms).
Why choose Ving Tsun? Well, it can be just as effective as Krav Maga (although you would have to add in your own weapons training. Krav Maga spends a lot of time on weapon disarms, which is something i don't think Ving Tsun covers. After all one was started by a nun and the other the Israelis). Ving Tsun can be extremely effective. Secondly Ving Tsun has more 'flesh' than Krav Maga. It has more history ....more tradition. Now, this might seem contrary to my prior post where i blasted tradition (and since my main system is jeet kune do it is even more ironic since Sifu Bruce Lee spent a lot of time dissing Ving Tsun because it was traditional), but it is always nice to have a little tradition. Especially when it is in an art (eg Ving Tsun) that still has more than sufficient combat elements to it.
Using car analogies Krav Maga is a Shelby Cobra. Super fast, amazing acceleration, and a lot of ooomph. The moment you strap yourself in you are zooming. But the car is not really that smooth, its steering could use some power-steering, and its tail tends to whip around when zooming past corners at high speed. Ving Tsun, on the other hand, is a BMW Z4. It is a fast 2 seater roadster (like the Shelby), but it is not as fast as the Shelby. It doesn't have the crazy horse acceleration of the Shelby. And even though it has oomph it doesn't quite possess the same raw testestorone that the Shelby has. However it is much smoother, has perfect handling, and has no over/under steer problems. It may not be as hard-@$$ fast as the Shelby, but it has a good mix of speed and smoothness.
If the Krav Maga/Shelby is a vodka on the rocks, then the Ving Tsun/BMW Z8 is a martini on the rocks. Same constituents, but one has slightly more bite and the other slightly smoother.
Hence Ving Tsun. And there is nothing like having a wooden dummy in the backyard to train your grandkids with (if/when you get them LOL).
But both systems are equally good. Thus if the Ving Tsun place is a mere half-mile further than the Krav Maga place you might as well go for Krav. Both are quite good.
Actually the best thing would be to go to both schools and watch a couple of their sessions. Most schools will let you watch for a week. See which suits you. Which teacher seems to gell with you. Which environment strikes your fancy. See if the pace is too slow, too fast, just right. Then make your decision.
That is the best thing to do.