Ok, so everyone's telling you that lists and polls are a poor fit, and they are - but you probably want to know why; Oded gave you a good place to start, but here are the gritty details:
Your question reads,
What C compilers are most popular in the industry?
I went to Wikipedia to check out the list of C compilers. It is very long and I think only some of them are really mature and used by industry. Please give a list of such compilers. Also, please give the answer only if you have enough experience. Thank you!
Last problem first: saying "only answer if you have enough experience" is worthless. What's "enough" experience? How would you know if I answer and don't have "enough experience"? Heck, if I jump on and say, "I've been working in this industry for 30 years and can say without a doubt that PCC is the only mature, industry-accepted compiler" - a complete fabrication btw - what grounds would you have to say I was full of crap?
This leads into the bigger problem: "industry", "mature" and "popular" are all undefined.
- Which industry? Desktop apps on Windows? Web apps on Unix? Games on ARM? iOS? Android? Embedded manufacturing / vehicle / communications control?
- What do you consider "mature"? Unchanged in 10 years? Version 6 or later? 90% spec compliant?
- How popular? Used by at least 10,000 people? 20% or greater market share within the industry? 20% or greater market share across all industries where C compilers are used? Responsible for at least 20% of all C-sourced binary code as measured in bytes?
And the single biggest underlying problem: you don't tell us why you want to know! Is this just idle curiosity? Or do you actually need to chose a compiler for something you're beginning work on? Because if it's the latter, we kinda need to know what! If you want to write the next great iOS app, learning that GCC is pervasive across all industries but VC has the edge on Windows won't do you a bit of good - there's a specific toolchain you'll want to use, and neither "popularity" nor "maturity" have much to do with why.
In other words,
You should only ask practical, answerable questions based on actual problems that you face.