The F-15 is faster at high altitude in it's maximum speed range (mach 2.5) as opposed to the F-14's mach 2.34. However, as almost any fighter Jock will tell you, the aircraft are hardly (if ever) pushed to these limits because of the massive fuel consumption rate ($$) and safety issues.
Speed tends to be more important at low altitudes, when a fighter has to get in/out of a target area quickly. Here, the venerable F-14(B/D) is king, having the best acceleration and top speed of 1.5+ at sea level, matching that of the SU-27.
In terms of manoeuverability, the F-14 B/D will more or less match the performance of the F-18C in a dogfight, but has far greater range, a better fire control (and missle reach) system and is somewhat more stable in the mud-moving job. While we're still on the topic of "dogfighting", it might be interesting to note that the F-14 has a better lift/drag ratio than the F-18 AND the SU-27 and will actually lose energy more slowly (out-manoeuver)than a Flanker in a tight-in dogfight. According to the russians, the Tomcat is also superior to the Flanker in terms of instant turn performance and rate of climb.
Basically, the reason the Tomcat is being retired is because of its high maintenance costs and safety record. The F-18E is more cost effective in this arena, and is much safer to bring-back aboard deck (mainly because of it's newer, all-digital flight control system... A similarly-equipped F-14 would do about as well) but it loses out to the Tomcat in almost every respect in the combat arena: far shorter range, poorer acceleration, lower speed, rate of climb, rate of turn, etc...
For what it's worth, Mc Donnell Douglas won't even give any performance data for the F (which is the REAL replacement for the Tomcat, not the E model) model Hornet, which it knows will fare far worse against the Tomcat due to its extra bucket and reduced centerline fuel tank.