What about encounters where there is combat, but that is not the main point of the encounter?
Some examples that spring to mind:
A) A puzzle where the PCs have to solve it round by round while engaged in a combat. I ran a modificed version of this to great effect.
The Riddle of White and Black | Save Versus Death
I also ran a modified version of the final encounter in the Siege of Bordrin's Watch. Basically a large industrial complex with lots of valves that need to be turned on. There was a puzzle regarding which levers needed to be flipped at what time to make the engine start up. This was complicated by lots of orc minions and one orc boss attempting to stop the PCs. Some bad guys would even unflip the switches if the PCs left them unattended. The combat was a complication to the puzzle adding urgency, rather than being the focus itself.
B) An athletic challenge. I once had the PCs climbing an ice wall. They were in a great rush and got attacked by harpies half way up. There was a line of ice giants chasing them, basically the bottom of the map moved up 4 squares a turn, if they went off the map they were ripped to peices.
The entire fight took place on a vertical battle grid.
The harpies would have been a trivial fight, but other factors included unsafe ice, falling icilcles, the potential for avalanche etc. As an example, dungeoneering rolls would tell you when/where the next icicle was going to collapse a column of the grid. Nature would also let you know where the bits of slippery ice that would make you fall down a few squares was.
PCs were constantly using skills and moving, trying to fight the harpies when they could. They wisely decided to provoke a lot of opportunity attacks rather than risk getting caught by the giants. The controller would levitate ahead, then give cover fire, sliding enemies away so companions could climb. He even use an action point and encounter fireballs to push the line of ice giants back a few squares.
The players described the encounter like a mad fusion of D&D, Frogger and Snakes and Ladders.
C) Social combats, where you are trying to convince the 'bad guy' to stand down and/or join you before he hurts himself or others. This could be a hostage situation, or a bad guy who can be redeemed before he does anything too bad. Like the end of many movies, the heroes can be fighting while talking him down. To make it clear to the PCs that this is not a normal combat, you could forgo the grid.
D) Timed runs through 'dungeons'. I had my PCs enter a burning manor of a crazed alchemist to save some valuable tomes (though they find later there are prisoners too). They had X rounds to get in, get what they could and get out. I even set a real life time limit. "You have until the timer goes on the oven, to be out of there or the place collapses and anybody inside dies"
This really changes the way people play. They simply do not have time for a combat. Sure the monsters appear on the grid, but they have to just knock them prone and run away. Judicious use of controller effects and wall spells really saved the day. At least until they got into a dead end and all the monsters converged on them. It was great as the players realised they could not hope to fight through them in the 25minutes before dinner. They were all taking incredibly quick turns to try and get as many of them down as possible before they could just run through provoking half a dozen OAs each. They intelligently killed all the enemies that could slow or grab, healed up then just charged out of there disregarding the OA damage.