The good old original eGo 1000 mah is your best bet... it's been reviewed and used by thousands of vapers for over a year. I've never had problems with mine. They'll last you a good 6 months (on avg) before needing replacement. The eGo PT is also a top. I've gone over 6 months with my eGo PT's. (I got mine at GoodProphets and I think Chris at VTs sells them now too). The eGo PT might be just what you need at this time. Just plug it into you computer and it'll charge as you're vaping. Just unplug and vape on the run, You can also charge it via the ego wall charger.
There are tons of new goodies on the market, just this year. The eGo now has DUAL MEGA CARTOMIZERS!!! These produce at 3.7v but they perform like a 5v (double the vapor)
There will soon be tanks out that look nice on the eGo. These super new tanks are the best of the best....
The Liquinator
The J-Tank (electronicstix)
The Cartonator (nhaler)
etc.
In short, you can't go wrong with an eGo or an eGo PT or both. They are still number one.
(the eGo-W has no reviews yet and it might be a ce2 tank which isn't near as good as the new polycarbonate tanks out on the market that have no fluff).