If you are interested in getting more involved with photography, any of the cameras you mentioned would be excellent.

The DSLR offers many more manual controls than the powershot and a large choice of lenses.

The DSLR uses a much larger sensor assembly than a Powershot camera; it will produce much less noise when using higher ISO settings.
Less noise gives a cleaner clearer picture.
The DSLR will permit you to shoot continuously and take photos at a rate of over 4 pictures per second. Great for pictures of someone sliding into second base.

..