what you can do is to sit down with a piece of paper, then list down the camera body that you have shortlisted
write down their pros/cons
list down also the additional things (like lenses/flash/batteryg grip etc) of these camera bodies
make you decision based on the camera with most pros, and also the best
Different people have different expectations and needs, so even for the same cameras (eg D90 & 550D), Person A's pros/cons will be different from Person B
Other than the camera body, you will also need to consider the lenses
for example...
I will prefer the the Canon 550D as I can get the canon EF 50mm f1.8(at about $120) to go with it. The Nikon's AF 50mm f/1.8D will be about $180.... but some people will say that the Nikon's 50mm lens is better than the Canon's 50mm...
So it's your own call if you think the extra $60 is worth it or not
maybe you don't want the 50mm prime, but that's just an example...
I will need to do more research on the gears... Will tryout your listing methods...
Thank you so much..