thesilentist just did a great job rounding up a collection of slim wallets on the market, covering everything from Brooks Brothers (relatively common) to Glenroyal (relatively hard to find).  

Card-holder type wallets are great, their low-profile makes it easy to slip into the pockets of dress trousers without creating an unsightly bulge.  In fact, I carry one everyday.  For those looking for a slim wallet, I recommend Coach’s waterbuffalo moneyclip card holder, it has everything you will need: two single-card slots in the front and a larger multi-card slot in the center, plus a money clip at the back - enough room for four to five cards and some cash.  The Coach’s card-holder is also pretty good value - price at around $40-$50; the leather quality is also decent, and will age with a nice patina over time.  The only drawback?  The single-layer leather is pretty pliable, cards with raised lettering (e.g. credit cards) will eventually leave an imprint if placed in the front-most slot.

For those looking for something more unique, I recommend one of these Goyard hand-painted card holders.  The leather is double stacked alleviating the imprint issue that Coach card-holders have.  

(Source: thesilentist)