If you are looking at total number of guns sold ( all semi auto's Double Action, Single Action, 1911 frames, etc ...) I think you'll find that the numbers will be skewed by law enforcement and military contracts with their large quantities but I would think :
1. Glock
2. SIG
3. Kimber
4 - 10 are anybody's guess ( Colt, Springfield, H&K .....,)
The higher end guns - custom gun manufacturers like Wilson Combat, Ed Brown and Les Baer are going to be well down the list and I doubt any of them are in the top 7 certainly.
If you look at it by caliber - I think Glock will still be number one (although I would never own one) - with the #1 caliber as
1. probably 9mm
2. probably .45 ACP
3. probably .40 S&W
4. probably .380
Most gun stores will tell you they sell a lot of Glocks - most of it based on price and their reputation of reliability - and the typical price tag around $ 500 - but a lot of them are shooters that are buying their 1st or 2nd gun and probably the primary market as under 40 years of age. I think the market for shooters over 40 years of age are probably buying more expensive guns and probably dominated by the 1911 frame. I'd be willing to bet that at least 75% of the custom market manufacturers are sold to shooters over 40 years of age ( Wilson Combat, Ed Brown, Les Baer ) where an average gun is about $2,500 .
You're asking a complicated question - and I'd suggest you will have to break it down by:
1. market share by Mfg
2. by caliber ( all models )
3. then by models
4. lastly by model and by caliber ( but mfg's like Sig are making dozens of models - as an example the Sig 226 lineup alone right now has 14 different models in 3 different calibers ......most vary only by finish, so it gets pretty cumbersome). But all my numbers are guesses based on what I see in my part of the country - not based on hard data.