I love this thread. Lots of experienced homebrewers and professionals talking realistically about how yeast effects beer. Ie: flavor, color, smell, floculation, attenuation, clarity. And a ton of noobs who think yeast is a simple issue. In one post somebody will complain about a beer being too sweet and then say that he likes his yeast. Hilarious. If your beer is not awesome, and you are simply dumping dry yeast in it will be hard to improve. Understanding the yeast life cycle and learning to nurture your yeast will give you the tools to fine tune your process to get a result you like.
At a minimum, for those of you using dry yeast, at least look into the importance of pre-hydrating the yeast, understanding its level of attenuation, its proper temp range and what types of esters the yeast will produce.
Good luck to all.
ps: There are a lot of mentions of US-05 on this forum. Surely a decent clean fermenting yeast. I challenge anyone who uses this yeast to ferment a beer with wyeast 1272 at 68 degrees and tell me the flavor isn't cleaner, you didn't achieve the same attenuation and the real benefit is that this yeast flocculates extremely well when given a wort that has undergone a strong boil.