What Dslr to upgrade to from a sony a230?

I'm going to be graduating soon and i will be gettin about $500 or more and i plan on selling my sony a230 so i can upgrade my camera. I want to upgrade because of its size, battery, and some other things. I'm leaning more towards a Canon or Nikon because i have owned a pentax and didn't find it very suiting. I tried out my uncles Canon EOS rebel (forget which one) and really liked it, having a button for each thing was very handy too instead of scrolling through a menu.

Any ideas as to what might suit me best
my price range is about 500-700 but a cheaper camera with more lenses will work too
(yes i know i'm picky)

Added (1). That is just what i know i will have, i will most likely have more just from some other things

Your budget is still a little low for a second camera. Usually people buy an inexpensive first camera and then start saving for their next, more advanced one.

At present there are two cameras I can highly recommend, the Nikon D3100 ($700) and the Canon T2i (550D) ($900). Both are equipped with a 18-55 mm lens, probably like the one that came with your older Sony (can only be used with other Sony Alpha dSLR's)

Before you buy, go into a camera store and hold both the 550D and D3100 in your hands and see which you like the best and which offers the quickest access to changing ISO, EV, white balance and shooting modes. Both cameras can shoot video in the Full HD mode as well as produce stunning still images. The one thing the Nikon has is the ability to auto-focus when in the video mode.

You can't go wrong with a Nikon or a Canon. They are both great cameras.

Why didn't you find the pentax suiting? Handsize? Button placement?

Canon
550D - small APSC sensor. Has some buttons. Not as many as the other choices. Cheap. Individuals with larger hands may find the camera too small.
7D - most buttons and customizable. Fits most comfortably in my hands. Still APSC sensor. (the best APSC sensors has to offer)
5D - less egronomic, but full frame.

Nikon (the descriptions are more or less the Same)
d3000
d90
d3

Selection criteria:
chooose the one that feels most comfortable in your hands.
Are the menus accessible? Do you know what the buttons do? Can you access them?
Is the camera too big or too small?

These are the only real criteria that matters when choosing a camera body. Then choose the cheapest one that fits your criteria. Always save money for better lenses.
Lenses get a little more difficult to choose. Everyone's got their preferences.