Balance (I own one) is an excellent and simple BC that will serve you very well for simple diving and travel. If it has a shortcoming, it is that there are few D-rings--one on each shoulder and one only on the left hip. I love mine, but I also own other BCs and BP/w for more "involved" diving.
TransPac is a classic. All the pluses of the Balance, plus additional adjustability and plenty of attachment points--will come in handy if you plan to dive wrecks and want somewhere to clip off a reel, pony bottle, back-up lights, etc. If I could only own one BC, this would probably be it.
OMS probably makes some good stuff, but all I ever hear about them is complaints about defects and customer service problems. Somebody please post something good about this BC for "balanced opinions".
theskull