Good results are results that get you into a good course at university.
What constitutes a "good course" is highly subjective. In my eyes, any STEM subject at most universities are definitely worthwhile (you idiots who dream of living inside a Cambridge professor's rectum should note that there are many many people who have highly successful careers due to their subject choice and work ethic, despite going to less prestigious universities -I know PhD students who went to places as low down in those league tables as Strathclyde who were doing the research for their doctorate at places like Warwick and Oxford. And you've all heard of the Higg's Boson? Peter Higgs studied for his undergraduate degree and postgraduate degrees at KCL and is now probably one of the more well-known theoretical physicists. Anyway, back to the point...). STEM subjects pay well and we need more graduates in those subjects. You've done well for yourself to get onto a STEM course in my eyes as long as it's a half decent place.
Arts subjects are different I feel. A degree in English literature is useless in the sense that it doesn't lead anywhere in particular, other than a generic graduate job. I don't care how competitive it is either, because at the end of the day, your A*s count for nothing in the real world (and I'm saying this from experience). If you are going for an arts degree, then I would say that good grades are the ones that will get you into a prestigious university, because you're going to be relying on the brand name come graduation time.
It's all a bit crass saying "A*A*A is amazing"and "AAB is poor". The only time you have poor grades is when you under perform by your own standard and the only time you have amazing grades is when you pleasantly surprise yourself. It's all irrelevant really, The only important thing is that it gets you onto the next step.