Andy_K 

It kind of depends on what you're using them for. For most uses any tube will do. I have a big box of patched tubes in my garage. That's what I use most of the time.

The most important aspect of tube selection is valve stem length. A lot of tubes have stubby little (~36mm) stems that don't protrude sufficiently from even moderately deep section rims. I like 60mm stems.

I do think some tubes are better than others, but even for cheap tubes the failure rate is so low that you'd really have to use a lot of tubes to distinguish a problem brand from bad luck. I like Continental tubes. They feel nicer than cheap tubes, and the valves have a better finish which doesn't weather the way many tubes' valves do (corrode would probably too strong a word -- I'm referring to the ugly patina that most brass valve stems develop). The Presta models also have removable cores, which is good if want to use sealant but can be a major PITA if you use a pump that threads onto the valve stem like a Lezyne.

If you patch your tubes when they puncture there is really very little practical cost difference between a $2 tube and a $10 tube. That said, the difference in quality between the best tubes available and average tubes is small enough that I'll buy cheaper tubes if it's more convenient. Sometimes I'll add a Continental tube to my online shopping to push my order over the free shipping threshold. In the rare case that I need a tube immediately I'll buy whatever the LBS has in stock.