Have you tried Ubuntu Certified hardware and encountered problems? Everything works fine on my Ubuntu Certified hardware: a ThinkPad and an OptiPlex desktop that both have Intel GPUs.
I had an optiplex desktop that did not work well. It was a giant pain in the ass to get video working properly, and it would often not wake from sleep.
OptiPlex covers a large number of models and hardware, just like "ThinkPad" does. I'd imagine that the Ubuntu Certified Hardware list specifies models that are known to work well.