I'm keeping a list of miniature companies that sell 15mm miniatures and appear to be going concerns.

Metal Miniature Companies

• Pico Armor/Oddzial Osmy
  Website ordered from: Pico Armor
  Notes: 15mm from Oddzial Osmy, also sells wide variety of 3mm
  Do I own any: 12 sets of 15mm
  Painted Image:
  
  

• Irregular Miniatures
  Website ordered from: Irregular Miniatures
  Notes: Huge range of Sci-Fi, Fantasy, Historical, excellent prices, 2mm, 6mm, 10mm, 15mm, more.
  Do I own any: 200 15mm, ~50 6mm, some 2mm soon
  Painted Image:
  
  

• Splintered Light Miniatures
  Website ordered from: Splintered Light Miniatures
  Notes: 15mm Fantasy and Historical
  Do I own any: Not yet
  

• Pendraken
  Website ordered from: Pendraken
  Notes: 10mm Fantasy, small selection of 15mm fantasy
  Do I own any: Not yet
  

• Khurasan Miniatures
  Website ordered from: Khurasan Miniatures
  Notes: Everyone raves about the detail. Lots or highly detailed 15mm, historical and fantasy/sci-fi
  Do I own any: Not yet
  

• Ral Partha Europe
  Website ordered from: Ral Partha Europe
  Notes: decent selection of 15mm fantasy
  Do I own any: Not yet
  

• Old Glory Corp
  Website ordered from: Old Glory Corp
  Notes: This one is in Pennsylvania, has similar selection to the next one in the list. 15mm Aliens, Horror, Frankenstein's laboratory and mostly historical, very little 15mm fantasy
  Do I own any: Yes. They are great. I even visited the factory.
  

• Lancashire Games
  Website ordered from: Lancashire Games
  Notes: Biblical through modern, can't find any fantasy
  Do I own any: Not yet
  

• Alternative Armies
  Website ordered from: Alternative Armies
  Notes: Large selection 15mm, including pre-built armies for lots of games. Fantasy, Sci-Fi, Historical
  Do I own any: Not yet
  

• Mirliton
  Website ordered from: Mirliton
  Notes: Smallish selection, Italian company. Pre-built Impetus, DBA and Hordes of Things armies.
  Do I own any: Not yet
  

• Copplestone Castings
  Website ordered from: Copplestone Castings
  Notes: Smallish Range, lots of barbarians.
  Do I own any: Not yet
  

• Rebel Minis
  Website ordered from: Rebel Minis
  Notes: Good sized range of fantasy, modern and sci-fi
  Do I own any: Not yet
  

• Victory Buy
  Website ordered from: Victory Buy
  Notes: Unknown scale, 1950s style plastic army men, with some sci-fi.
  Do I own any: Not yet