Which camera should i choose? (Nikon D5100, Canon 60D, Canon 600D, or Canon 650D)?

I've been asking a lot of questions on which camera would be best for me. I chose nikon over canon at first. I currently only have a nikon d5000 in which i've had for almost 3 years.right now i'm trying to decide on which of these four cameras i should choose: Nikon D5100, Canon 60D, Canon 600D, or Canon 650D.
I want a camera with good/great picture taking quality. I also want it to have good video quality if i want to take a video. I hear that Canon has better video quality than Nikon but i'm use to Nikon and i still wonder how good Canon's camera's are with pictures. I like to take pictures of plants/flowers, animals, food (sometimes), and people.i'm having a hard time deciding on those four.

Added (1). The D5000 doesn't have good video quality and it's hard or me to see myself when i'm recording video.

Well, I for one am totally in the dark as to why you are abandoning your D5000
what is wrong with that

Seems to me you need a new toy
sorry, i may be wrong

Maybe you could also tell us what lenses you have

Here's all of them side by side, http://www.dpreview.com/...on_eos650d

1) it is RARELY a good idea to switch cameras systems.
2) You seem to have missed some of the enhancements that Nikon has released recently with the D3200, D800 and D4
3) In the next two quarters, Nikon will be releasing the replacement cameras for the D5100, D7000 and D300s.

Here is how the entry level Nikon D3200 sensor compares to the Canon 60D, a much more expensive dSLR (marketed against the D7000).

http://www.dxomark.com/...nd3)/Canon

As you can see, the sensor performance of the Nikon D3200 and D7000 are in a class beyond the Canon 60D.

I don't know where you hear that Canon has better video than Nikon, but there are a few things to consider

* You are buying a still camera with a video feature, NOT a video camera
* Only Nikon makes a dSLR that shoots uncompressed video (Nikon D800 and D4)
* If your goal is to shoot video, you may want to read this:

http://www.luminous-landscape.com/reviews/camcorders/cam-cam.shtml

There's NO reason why you are not getting great picture quality with the camera you have.

Here are two samples shot using an old, old Nikon D100 with a 6mp sensor

Whatever quality images you are producing now will not change by purchasing a higher resolution camera. NOT without your learning to enhance your skills using your camera, Nikon or Canon.

Picture and video quality depends on the ability of the user. The camera is only a tool. If you can't get decent pictures and videos with your old dSLR, you can't either with a new one.

If you insist on buying a new camera, it would make sense if you stick to Nikon so you can share lenses with your old camera. If you decide to sell your old Nikon, get the most expensive Canon you can afford for (hopefully) more satisfaction.

Just know that all dSLR's are basically the same. What you can do and get with one, you can with another IF you know exactly what you are doing.