Well PC's are always at the forefront of technology and have as you say, more flexibility. But, what you have to remember is to develop for the PC is more expensive due to the game needing to be tweaked for the various hardware available. So often you'll find that the PC release of a game thats not PC exclusive, will be after the console release date.
FPS games used to be solely on PC(few exceptions but none really worth mentioning), the mouse gives greater accuracy(and sure, still does) however casual gamers are finding it nicer to use a console in a living room where they can all sit around a large tv and play.
However the PC counter point to that is the Home Theatre PC, these are often small PC's which often pack the same power as a dedicated gaming PC(although do generally cost more). They can plug straight into the TV Via HDMI and when plugged in with a good wireless keyboard/mouse or even gamepad, will be a good alternative to a console.
I own a PS3 and have extensively used a 360 and had a quick play on a Wii, but PC's are where i love my gaming, especially FPS and RTS games. That's not to say i'm a PC fanboy as my PS3 is used daily for Little Big Planet and i've recently completed Uncharted again. But given the choice of playing Resistance 2 on the PS3(online or offline) i'd rather settle with the PC.
It boils down to this:
If money is no object or you don't mind going minimum of £500(about $700) excl monitor then you can get a PC that'll give you an experience better than a console for graphics(and controls IMHO when it comes to FPS) and if you spend a bit more of a small living room PC then it'll have the same features as a console. Hey if you like your Xbox controller get the PC Xbox Common Controller, you like your PS3 controller? plug them into your PC and download the 3rd party drivers. You can use your Wii controller too but i've forgot how. People say PC gaming is dead, but it's far from.
However, if you are on a budget and want a system that'll do a good job of playing games without compatability issues but don't mind spending more for the games then a console is the way forward. I love how consoles have the "plug and play" type experience, plug it into a tv, connect wirelessly to the internet(for ps3, or pay extra for 360) then switch on the controllers and off you go. Both are very good, PC and Console, but for me its the PC. However most people choose console, because at the moment casual gaming is the in thing this coupled with the dropping price of the consoles then more time, effort and money will be spent on games for them