I think it's very hard to do a head to head comparison because you can select different avionics packages for these planes.
But just looking at the platforms,
Su35 (and Su27 derivatives) - the most agile of these, despite it's size, with optional thrust vector engines, good range without external tanks, front and rear radars with bigger range than F15, and able to fire rockets backwards. It can do things that no other plane can.
F15 - very good, excelent track record, but old. Sorta like B52. Tried and true.
There is a reason why F22s are being built at the cost of 250 billion, and that reason is the Su27 and it's derivatives.
If F22 lives up to the stealth hype, it will be very tough to match.
There is also S-37 being built in Russia, which is one weird looking plane derived from the flanker. Unfortunately Suckhoi doesn't have anywhere near as much money to develop it as it did during cold war for Su27.