When I got my job after after finishing school I realized that I needed to get more suits/button downs and ties. I really didn't know much about dressing for business at the time, so I just stocked up on JAB mostly on the advice of the salesmen.
Shirts
Executive - DO NOT BUY. Their cheapest line. I had two but gave one to good will and another to a friend. Cheap material, lots of shoulder padding, fits huge.
Business Express - A slight step up from the Executive, but not a big one. Styling is very similar; with big shoulder pads and cut for a very large guy. Improvement comes from material quality.
Traveler Tailored Fit - These will still need a good deal of work from your tailor. They are cut for an overweight man, and the shoulder pads are quite substantial, with fairly low armholes. On their description of the Tailored Fit line they actually say that they leave the arms the same as their regular cuts. I actually like the fabric on this one, both of the lining and the suit itself. It does however fail the "Do I actually still wear it" test because the pants are pleated. Unfortunately, if you want flat front pants your options will be VERY limited at JAB.
Shirts
Traveler Tailored Fit Non-Iron Button Down - I wear a non iron button down to work every day. I actually like these. While not the best looking shirts in my wardrobe, I have 5 or 6 of them and wear them to work all the time. While not as nice as some other non-irons, they are super easy to take care of and are very durable. If they drop down into the $35-40 range, worth pulling the trigger if you have to wear button downs to work every day.
Tailored Fit Polo - Not a huge fan. The material, while soft, is very thick and heavy. It also is still pretty big and baggy. My Merona Polo's from target fit closer. I'd stay away when there are so many better and cheaper options for polos.
Ties
I got a few standard ties free when I bought suits. Not really impressed. While better than ties from target, they aren't that special. Not as good a quality as you can find at the tie bar, Marshall's or Nordstrom's Rack. Also most of their ties are 3.5 inches wide. Too wide for my tastes.