I'm in the same boat. I've been reading reviews, asking questions here, etc.
Based on reviews pretty much any of the major brand entry level cameras are good values. What it comes down to are the small differences and expandability.
How does one camera feel in your hand compared to the other. How do you like the control layouts. Do you have a particular type of photography you want to pursue and in what way. Do you want more convenience or to challenge yourself.
I started out considering the Sony A35, then read some here and considered things like lens choices and then looked at the T2i, then the Nikon D3200 came out and I was looking at that, but right now I'm back to the Canon. Why? Well, my main interest is macro. I initially turned to the T2i because Canon makes a pretty awesome macro lens that does 5:1, the MP-E65...but that lens is $1,000 and it only does macro. Add to that a pretty awesome flash unit in the MT-24 which goes for around $800 and suddenly the set up is staring $2,500 smack in the face. Way above my budget. So, more reading here about macro and how it can be done, things like reversed lenses, extender tubes, etc, then learning about Nikon lenses and that was leaning me back toward the D3200. Older, used Nikon lenses for comparatively cheaper prices would mean the ability for me to have options that I would normally have to wait much longer for when you start looking at glass that is upwards of $1,200 for good stuff.
Then I learned that the focal plane on Nikon cameras is longer than Canon's...which means adapters are available for the Canon that can mount and shoot Nikon lenses and maintain proper focal plane length. Suddenly the lens options have increased considerably. Yeah, the D3200 is 24.2MP, which alone doesn't mean better images, but does provide more crop ability (which can be useful in macro), but it doesn't give the potentially broad range of lenses (can't put an adapter on the Nikon and use Canon lenses) and there's no AEB in the D3200 (HDR is a secondary interest for me). Sure, shoot the exposures manually, but no AEB in the camera means no hand-held shots for HDR. Not significant, but a consideration.
Going back to the Canon means I do have the opportunity later to get that MP-E65 lens when my funds allow it, but also have the ability to find and use a broader range of older (and potentially cheaper) lenses to tinker and learn with in the interim. And...the T2i does do AEB....and it's 18MP...not quite 24.2MP, but a few MP more than the D3100 or D5100.
For me, right now the T2i presents the best option in my opinion. I'm still reading though and not going to run out and get it just yet. I may learn more, or something else that might sway me back to a Nikon or a Pentax, or who knows.
If it's not obvious, I tend to obssess over things and sometimes drive myself nuts worrying about details that may or may not matter, especially when contemplating what amounts to an expensive purchase for me. The reality is, either the Canon or the Nikon will probably suit me perfectly well, but I need to be comfortable with my decision, so to get there, i have to "wring it out" so to speak.