My recommendation is to go to some shops and take a look at what dSLRs are available. Don't worry about specifications or brand name (and whatever you do,
don't let anyone convince you that megapixels are the most important thing)... just play around with them, think about which ones you like the look and feel of, and that will help you narrow it down.
That probably wasn't what you wanted to hear. But I can't recommend the best camera for you to buy because I'm not you. Looking at your requirements...
- You want more "control over lenses" - any dSLR system will provide interchangeable lenses and the option of full manual control over focus and exposure.
- You like landscapes and portraits - any dSLR system has the lenses to make this possible.
- You're considering a fisheye lens - to my knowledge every dSLR system offers fisheye lenses.
... so nothing there really points you toward one system in particular.
It's easy to put too much thought into what camera to buy, and not enough into the lenses, flashes and other components of the dSLR system. On the other hand, I believe it's also possible to worry too much about the 'system' when any system offers far more than the majority of SLR owners will ever own. We all have different priorities and requirements in a camera body and in a 'system', therefore to my mind a trip to the shops to handle the cameras is as good a place to start as any, and probably a lot better than starting by looking at spec comparison charts.
As for lenses, well you haven't made it easy for us

A fisheye lens is a fisheye, it won't double as anything else. So if you wanted 2 lenses to do everything, and a fisheye was one of those lenses, then the other would probably have to cover wide-angle all the way to a telephoto length suitable for portraits. You could get a do-it-all lens like an 18-200mm, or you could have two separate lenses to cover that range. I would be inclined to forget the fisheye at first and concentrate on one or two more conventional lenses, since you yourself suggested you might get bored with the fisheye.