A follow-up regarding mig-25... Without going into many details, the mig-25 is one of the more challenging threats an F-15 driver faces, because it really is fast and high-flying. Different opponent fighters will have different roles, so the scenarios where an F-15 driver faces a mig-25 will be biased in favor of the mig, simply because the mig's mission would be tailored for the capabilities of the mig-25. Chasing down our AWACS or other high-value assets (such as U-2, jstars, etc), or intercepting incoming bombers are examples where the fact that the mig-25 turns like a truck simply is not relevant. Likewise, the mig-29's small size and limited range wouldn't likely be a deciding factor when flying into a nest of the little suckers. And an su-27 in a forward offensive counter-air role or escorting their own strike package may not have the luxury to park in one spot to mix it up in a dogfight.
All in all, I still prefer the F-15 over all of them, knowing full well what their real capabilities are. For that matter, I still prefer the F-15 over the viper or hornet because of the eagle's versatility, loadout, range, and the performance edge it has over most other aircraft in most flight regimes. It has lots of gas, can go very high and fast, can bring 8 amazing missiles to the fight, and has a radar the size of that new video scoreboard monstrosity hanging in the new dallas cowboys stadium. That radar matched to the amraam, employed from over 40,000 ft at mach 1.5+, is absolutely superb, and the F-15 is still one of the few fighters in the world with the gas and low altitude speed to intercept and chase down low altitude high speed intruders as well. System integration is outstanding, and the pilot has a great view of the world from the high seating position compared to most of the russian designs which have the pilot seated relatively low, with somewhat restricted visibility. Add a helmet mounted sight and aim-9x, and the eagle still matches or surpasses the mig-29 and su-27 *as a complete system* even in a close-range dogfight.
The F-22... That plane is in yet another class entirely. Awesome capability, its main drawbacks are that it is tough to maintain and very expensive. The JSF won't come close to the F-22 in the air to air realm and it can't carry half the air to ground loadout as an F-15E, but it's going to be a really capable F-16 replacement if it works as advertised. The next gen russian fighter... I suspect that they'll have trouble getting and keeping the radar cross section down below that of a super hornet, but I have no real data other than putting a critical eye on some detailed photos I ran across.