to quote Thomas Hogan from no later than today:
"A lot of cameras are bought because of cache, something to which style contributes. A lot of M9's and D3's and even 5DII's hang around people's necks more to show off their wealth and good taste rather than to shoot better pictures. "
...
"Let's face it, even the lowest of low DSLRs these days is a pretty amazing instrument. It'll take great images, even in low light, that'll print well up to the size (and beyond) that you can really consider doing at home. Sure, the build quality might not be robust and a few features you might want aren't there and a few hand-holding things you don't want are, but as a basic "take more-than-competent-photos-in-almost-any-situation device," the low-end DSLR is mature and capable of excellent work. We all need to spend more time maximizing what our current tools are capable providing us, because I'll bet that 99.9% of us are underutilizing what we've got."
Any of the A580, D5100 & 550D will do what you want & in spades.
Yes, they'll all have their own foibles & areas where they can score points over the opposition but they are pretty closely matched.
It's handling time though as many folk have walked into a shop intending to buy 1 camera only to feel that they were more comfortable with another.
