I've used a lot of C/C++ compilers over the years, and the two compilers marked in my memory as having enough bugs to be noticeable and disturbing were Visual C

I've used a lot of C/C++ compilers over the years, and the two compilers marked in my memory as having enough bugs to be noticeable and disturbing were Visual C++ 4.1 (so notably bad that MS essentially apologized for its screwup and conceded that 4.2 was largely about fixing 4.1's problems) and CodeWarrior for Mac (pretty much any version, I think...I never tried the Windows version, but the thought of it makes me shiver). CW had a pretty nice environment to develop in compared to its contemporary competitors, but it just didn't have a solid compiler.