I don't really think power creep is the only way to one-up other mods. I have enough methods of flight and material generation. Whether I use a Big Reactor or a bunch of Pink Generators, I'm still producing nearly infinite energy. Whether I use a Mining Drill or a Quarry, I'm still obtaining nearly infinite basic resources.

Yet still, some mods like Chisel, Carpenter's Blocks, and Forge Microblocks are some of my favorites because they provide something different that will be very very hard to one-up. I love Archimedes' Ships and Funky Locomotion because they provide opportunities for cool machines without simply watching the number of iron in my AE system increase. I love Twilight Forest and Aether II and this other mod with alien worlds (name escapes me) because they provide cool-looking blocks obtained through exploration. I love Rotary/Reactorcraft because their machines look so cool with the spinny bits and glowy parts.

How many mods have pulled off an elevator as cool-looking/functioning as Pneumaticraft? Seriously though, we need more cool-looking elevators in mods.

One-upping other mods can be done by making your numbers bigger than everyone else's, or by making your stuff cooler than other mods. Cooler != bigger numbers.

Sure Draconic Evolution lets me be quite literally invincible, and I'll wear its armor just because it's the best. However, I'll still go for IC2's Quantumsuit and Botania's Flugel Wings because they look so cool. However, I'm much more proud of the Chisel/Carpenter's/Microblock decorated spaceship I've built than anything else. It feels like I'm playing Minecraft rather than an MMO where best-in-slot is better.