I'm fairly new to the CI-scene and I've been concentrating my efforts on CruiseControl.NET, using NAnt and Ivy to build my .NET projects.
I've found that CruiseControl.NET is very adaptable to lots of other tools, such as NCover/NUnit/etc. They all plug into this and integrate the results for a combined build process.
I'll be looking into TeamCity in the near future for my own interest, but I think that CruiseControl does a good job, but only as good as your build-scripts! If these are pants, then your builds can only be expected to be that good.
But in summary, CruiseControl.NET is a good solution, but I'm yet to find out how good the competition is in comparison.
