Guinness vs. Murphy's is a reasonable debate (I'll take Guinness...I think it has a little extra "bite" that makes it more sessionable, plus it's more widely available on tap).
There's no comparison between either of those and a sweet stout like Young's or a monster like Fat Dog. Different beers for different situations, I'd say.
I'd rather Murphys than Guinness. A couple reasons.
1. Guinness is more mass produced, there for quality varies (IMO)
2. Guinness around here comes in 14 ounces cans for almost 8 bucks, Murphys comes in 16 ounces cans for 6.50 accross the street from me.
Other than that, I'm really just a go against the grain kind of guy. Been to alot of bars and only found Murhpys at one. I'll get a Guinness if all the bar has is BMC.
Between the two, I'd rather have Murphy's. If I could pick any commercial stout, I'd choose Great Divide's Oak Aged Yeti. Of course, that's pretty much a completely different style (imperial + wood aged). For a more traditional commercial stout, Young's Double Chocolate has my vote.
Old Rasputin comes to mind as well as Clipper City's Heavy Seas Imperial Stout, and I also like a good oatmeal stout better than a dry stout. Among dry stouts, i like Beamish- seems to have a little more smokiness to it.
I know all these opinion poll threads are just for fun and I enjoy it too, but isn't this one in particular a little like asking, "Whose baby is cuter, yours, mine, Brad Pitt's, or some other one?"
Of the two, I'll take a Murphy's. However, as far as widely available stouts go, I'll take a Guinness Extra Stout or a Young's Oatmeal Stout over anything!
If it's between Murphy's and Guinness standard cans or bottles then I pick Murphy's - it's cheaper here, and I like it.
That said, I <3 Guinness Foreign Extra Stout. It's the bizzomb. But I'd give a nod to either Old Rasputin or Great Lakes' Blackout Stout if it's a wide-open "what do I want to drink?" choice.