It is a common misconception that the camera you use has anything to do with the final images you get, hence questions such as yours, "Which camera is the best?"
It is very good that you have taken a liking to photography which will please you no end.
However do keep in mind that cameras do not produce images themselves: the photographers do. "Any camera can record what you are seeing, but you have to SEE" is a famous quote by a well-known photographer.
To asnwer your question: "What camera can I use to take these kind of photos", the answer is "Any one". It is the lighting, composition, depth of field and a few basic rules in photography that makes a photography stand out from regulation snapshots of which are many. It is NOT the camera that makes a photo stand out, it is the one who uses it. Ansel Adams, probably the best landscape photographer is reported to have said "The most important part of a camera is the twelve inches behind it"
"If I get a good camera, can I take good photos with it?" is akin to asking "If I get the finest paints and brushes can I become an award-winning artist" or "If I buy the word processer that J.K. Rowling uses, can I write a best-seller?"
Get the point?
Give a profesional photographer a disposable camera and he will still take a stunning photograph. Give a man in the street the best commercially-available, hyper-megapixel camera with the best lens and he will still take crap.
Any modern camera is good enough to start and enjoy photography. Go for an entry-level camera such as Nikon D40 or Canon 450D that have been best sellers in that category and you cannot go wrong.
The biological equivalent of the question "Are camera lenses really necessary" is "Do we really need our eyes?". If anything, the lens is the second most important component of a camera, after the person behind it.
Read the following link, it is most likely the most important article you will ever read on photography.
http://www.kenrockwell.com/tech/notcamera.htm
P.S.> The EXIF data on photos in the Flickr link shows many of the photos have been taken using a Canon 400D, which is the predecessor of the entry-level 450D I mentioned above, which should pretty much convince you even if my answer didn't.