What is the chain of importance in analog system ?

I think the turntable is the most important componet in an 'analoge chain' and this is where one should start. The success of a record playback system depends more on its mechanical interfaces/synergy than on its electrical componet. If I had to make an order of effect it would go like this:
1) turntable
2) tonearm
3) cartridge
4) phono
Cartridge/arm matching is important as is cart mounting, alignment and tracking angle.
That being said I would pick my table first,then cart,and pick an arm based on the cart. Once you've got that together a dedicated phono could be something to extract that last ounce of performance out of your rig. Top notch electronics can't make up for poor sources, but a good source can make a pedestrian rig sing.(Isn't that why CDs took over in the mainstream?)
I do think the cart is responsible for the sound and resolution of your system and the turntable/arm responsible for extracting the most out of the cart. That's why I started with the TT.

I think the phono stage is the most important because without it you can't play a record(sarcasim).This is like saying the record is the most important. Yes, the vinyl is the reason for the playback system but isn't that stating the obvious? And puting a playback system together is alot like puting a ball team together like, let's say the Yankees. Just because you have the highest payroll or the best player at a position doesn't mean you'll have the best performing team (maybe this analogy isn't quite right considering NY's success this year). Jaybo is right, your expectations should be realistic. The turntable is responsible for bass extension, the rhythm and pace, and what makes analog sound better than digital. It affects the ultimate S/N ratio either adding noise or getting out of the way and letting the arm/cart do its thing. Belt drive is the way to go. Try reading some of the old Linn Lit. It makes sense.
http://www.linn.co.uk/music_systems_sondek_LP12