I have a friend who pays an absurd amount of money for a T1 line, and in most situations my boring old cable provides me with faster download speeds and often a better ping. The only real advantages are that with a t1 you are unaffected by other users and that you generally get more upload (its parallel) than you would with cable. Not worth the money imo.
T3 on the otherhand might be an interesting option
Thats up to about 45mbps both ways (while a t1 maxes out at 1.5mbps both ways). If money was truly no object, I'd go for an
OC line. A full OC48 can reach almost 2500mbps...absurd bandwidth...but thats gonna cost you probably a few million dollars per year (probably even more if its going to a residence and not a business or university...an OC3 costs like $250,000 per year, and an OC48 is 16x faster).