I've recently stumbled across a new (new to me, anyway) line of 1/48 and 1/72 aircraft decals from an Italian  company called SkyModels.  They produce a decent number of sets, mainly of WW2 aircraft.  Of particular interest to me are the Italian aircraft sheets, but they do make others. 

Printed by Cartograf in Italy, each set is overflowing with markings.  Literally.  The decals themselves are crisp, perfectly registered - and previous experience with Cartograf indicates they are easy to apply and respond well to setting solutions - much like Aeromaster or Cutting Edge.

Each set (P-51 B/D and Macci MC202 shown) provide markings for far more aircraft than you'll find on almost any other manufacturer's sheet - 20 subjects are not uncommon.  Many of the markings I've not seen on other sheets, though I'll admit I don't have an encyclopedic knowledge of what's available. The ones I can verify from the references I have on hand appear accurate.  Included is a small booklet with black and white side profiles of  each aircraft, with overhead/underneath drawings as necessary.  Each one has paint call outs in addition to the decal placement notes, and a handy color/paint equivalent chart at the back listing colors from various paint manufacturers (Humbrol, Molak, Tamiya, Gunze & Mr. Kit, plus the closest FS595B match).

All-in-all, they're well worth checking out, especially if you want something that hasn't been done to death by the rest of the modeling public.  You can get these sheets through Pacific Coast Models [http://www.pacmodels.com/]

Editors note: Obviously John needs to stumble around in Modeling Madness more often. Sky's sheets on the 1/72 B-17, 1/48 Macchi C.200 and 1/72 Aermacchi MB.339 have been up for a while. :0) Having used the Macchi C.200 sheet on the AstroKit model, I can vouch for the superb fidelity and ease of use. I notice that the P-51D sheet also suffers from having US insignia that have the blue surround a bit too thin, a failing of the B-17 sheet as well.