The Hollywood Reporter ranks the top 25. Their ranking system may be perfect for you, or may be flawed. But read about those 25 and it will give you a very good idea about what some consider to be the best options.
Before you blame your camera or your lens, what are are you using for lighting? What light modifiers are you using? What metering system are you using?
Looks at any Behind The Scenes images of a typical video shoot and ask yourself: does my lighting setup look like that? Of not, chances are the problem does not lie with the camera.
Mete, to answer what I suppose is the other question within your question: many consumer camcorders have a fixed bit rate of around 28Mbps. (Some, like the GH4, can shoot up to 200 Mbps.) Some also have higher color sampling rates at lower frame rates (4:2:2) than at lower frame rates (4:2:0). If you are wondering whether footage shot at 25fps and 1/50th of a second looks different than 50fps and 1/50th of a second, discarding every other frame, the answer is "it depends". It depends on whether your video scene is complex enough to break the quality of the codec being used to encode your video. If you shoot a simple scene, it might look find using 14 of the 28MBps it's encoding. If you shoot a scene with lots of detail and motion (leaves blowing in the wind is a typical example) the eye might be well-enough fooled when playing 50fps footage at 50fps, but it might see the breakdown of missing every other frame--and not having the compression bandwidth to give you better detail.
Higher-end codecs with better compression/more bandwidth will forestall these problems. And higher-end cameras, like RED, let you set how much compression you want (subject to their 300MB/sec maxima, which is 2400Mbps). Can one set a compression rate too high and get bad artifacts on a RED? Yes. Can one push a consumer camera over its limits by discarding half (or more) of the frames it shoots? Yes. But where, exactly are the limits? It is scene dependent and it is person-specific. Which is where experience comes in: learn your gear and your image workflow and you'll know where the limits are, just as you do with highlights, shadows, and everything else that literally makes or breaks your images/clips.
Yes. A typically very large difference is that 25 fps footage will shoot with a 1/50th second shutter speed, which is completely impossible at 60 fps. 60 fps footage is typically shot with 1/120th of a second shutter speed, which will look very "saving private ryan" when converted to play at 25 fps. Does that help clear up your confusion?
The best one to use depends on your goals. If you are an American, fund-raising from Americans, looking to release in America, and hoping that it will screen widely in America, then shoot 24p. If you are European, fund-raising from Europeans, looking to release in Europe, and hoping it will screen widely in Europe, shoot 25p. If you are somewhere between those two, figure out which you are closest to and choose. It is a binary choice. You cannot shoot both. One will be better than the other for the "native" market. You have to pick your market, then make your film. Then, if there's demand from the other market, you can hire a post house to do a high-quality conversion from 24p to 25p, or vice-versa, depending on what you originally shot.
I have three of the four Nokton lenses (17.5, 25, 42.5). I love the consistency between them. For the ultra-wides I use the Panasonic 7-14 f4.0. It's sharp as heck and very rectilinear. And it gets very wide. When I need to go wider than 17.5, I like having the flexibility to decide how wide to go.