Alum,still and harsh for the most part.
Steel,smoother and a tad heavier but nowadays not enouth if you just ride.Like alum,beeter frame,less or no flex.
Carbon,smoother ride then steel but as above,frame built matters.Some stiffer then others.
Ti,best of everyhing as the pro's say,its their choice if they could choose.
If i was to look for a new bike today,it wouldnt be alum because i dont race and i;m older so i want less jarring ride.
Not steel because i have it already and it's nice,better then my 2 alum i had.
I would be looking at xarbon,Giant Tcr1,5200,roubaix carbon,supergo's brand bike,cervelo R2.5
Ti is bucks so litespeeds new one for $1999,after that i dont know,LeMond but its $$$.