I have 3 DSLRs: Canon Rebel XTi, Pentax K10D and Nikon D5200
My experience and preference (obviously bias, so keep that in mind):
- I will not buy a Canon again, I just have not had a very good experience with that camera at all.
- My Pentax K10D has been a great camera for me. I was able to buy a whole bunch of relatively inexpensive k-mount lenses off ebay to put together a pretty good collection. That camera body is built like a tank and is water resistant. I use this camera when I am in environments that could damage my camera (workshop, mountain climbing, etc...). This thing would probably outlive me...
- The Nikon D5200 is my most recent camera and I have to say that it has been AWESOME. Best camera I have owned by far. This thing can even make me look good, which is saying something...
I highly recommend Nikon as a brand, I have never used a Nikon I did not like...
Here is an example from the Nikon D5200. This is taken with the kit lens, the on camera flash (as a flash trigger) and an off camera flash (triggered by the on camera flash). This was a very low tech setup in my living room without anything special going on. No diffusers or fancy photo equipment...