How to find the good CD recordings?

I'm new to high end audio but have a decent system. One of the things I've noticed with this new (old) system, is that some of my CDs which I used to think sounded fine just don't sound all that good anymore while some of them sound great. A lot of these CDs are 30 years old and came from CD clubs (remember those?) and typical record stores.

I've noticed in particular that some of my Led Zep CDs just sound a little flat and a little shallow while some of the Pink Floyd and Rush CDs sound quite good. 

Is this just a matter of Floyd and Rush having higher production quality from the beginning? 

Would later "remastered" Zep CDs sound better? Is "remastered" always an indication of better or superior quality? Is it just marketing hype sometimes?

Anyway, with this new system I am inclined to buy the best quality recordings of any newer music I buy and possible replace some of my old favorites.

So is there a place on the internet where one can go to get reviews of the actual recording quality and not just the music itself. I don't see iTunes or Amazon as particularly useful here. At this point I am not interested in pursuing vinyl or high end audio files. I'm still just getting my feet wet and CDs seem like a cheap way to do that.

Any assistance much appreciated,

George