In my years of running tabletop games, I have been blessed with a lot of very cooperative players. They don't necessarily cooperate with me -- some of them get pretty obstreperous in-character. All of my tabletop games are designed around the premise that my players will show up with laptops and smartphones and will be Googling things like cracked-out little internet monkeys. It's much easier than arguing with them over turning all their gadgets off while we're playing, plus if you're playing with a load of IT geeks, giving them the idea that the overt solution to the puzzle is not on Google is kind of awe-inspiring, and more than a little frightening. Plus it means I can directly enforce the rule that if you're too busy staring at the screen to give me an action when I ask what you're doing for the round, you officially Lose A Turn To Wikipedia, and I skip to the next PC.

I personally encourage creative loophole abuse, because I think it's funny. I've been known to do it myself. I don't min-max much, because it's goddamn tedious, but I do tend to read rules very carefully when I get a whiff of railroading. Keeping the GM on his or her toes when I am a PC is my job.

I used to play a lot of D&D back in college. 3E had recently come out, and I have to say, that that the first round of those Castle Greyhawk things were proofread by people who didn't do much math, and had never played with the sorts of PCs who used to submit 59pp Wishes in an effort to make sure there were no monkey's paws involved. One of my crowning moments of awesomeness was in a game where I was playing a sorcerer/bard and the DM attempted to herd the party into an adventure that involved sneaking around and stealing something from a large and testy dragon, then getting back out again without being toasted. I don't actually know what was supposed to happen, because as soon as we crept out onto a narrow ledge that overlooked the main cavern where the dragon slept atop his glittering hoard, I pulled out the Player's Guide and initiated the following conversation:
"I cast Summon Creature."
"I summon a Celestial Bison."
"You can't do that, there's no room on the ledge you're standing on, it's only a couple feet wide."
"I didn't say I wanted it on the ledge."
"It won't fit in the tunnel either."
"Why would I want it in the tunnel? That would be stupid, it would block our escape route. The rulebook says I can summon the thing anywhere within a 25' radius, at my discretion. I summon the bison directly above the dragon's head, as high up as I can get it with a 25' reach."
Like I said. The 3E rulebooks were very badly proofread. We had to pause the game while the DM looked up the rules for calculating falling damage, the rules for calculating damage for an arbitrarily large blunt object falling on something from a great height, and the average size and weight of a Celestial Bison. I don't think we killed the dragon, but we certainly knocked it out, which made most of the rest of the module null and void.

That particular bard was Chaotic-Neutral, which I don't normally play. It was partly for revenge -- that DM was somewhat obnoxious and had a tendency to stare at my tits while we gamed. I figured he deserved it. That was the third or fourth character I'd rolled up for one of his games, and I was getting tired of the rules dickering, so the first thing I did was a thing I knew he hadn't planned for. I introduced her a bit after the beginning of a session that everyone else had already started, when they and the townsfolk were busy trying to keep a load of evil wererats from taking over the marketplace.
"All right, you enter the town square and see a crowd of people locked in combat with giant rats."
"Are any of them paying attention to me?"
"Uh... no?"
"None at all?"
"No, they're busy with rats."
"Okay. I steal a sack from the nearest market stall, and then steal anything that will fit into it."
Dunno how that one was supposed to end either. He tried to tell me at a later session of the same campaign that I absolutely could not talk my way out of the plot he was about to start. So I promptly did. I am personally frighteningly good at bafflegab, I was playing a character whose Charisma was through the roof, and that DM was reluctant to argue with actual dice rolls. Cleaned out an apothecary; pickpocketed most of a pub with the party rogue, then escaped the resulting fight by casting Light on another (Lawful-Good) party member just before he climbed up on a table to try to talk the crowd down, and then running like hell; then stole some horses and went galloping out the front gate with our very valuable quest items while the party Paladin stared stupidly after us and kept repeating, "I'm sure they wouldn't leave without me!" After pulling this a few more times, we ended up giving said Paladin a crippling fear of elves.

The Paladin's player thought this was hilarious. He was traditionally our party tank, although he normally preferred playing barbarians -- the player was a very bright fellow, and enjoyed the challenge inherent in playing someone creatively stupid. In a separate game, he was our faithful half-orc barbarian damage-sponge, Raugh Hnergh. He helpfully informed us that his Orcish name, given him by his orc-mother's tribe, translated into Common as, "Maybe the kobolds ate your baby." He defeated more than one trap and strongbox by employing what he called 'orcish lockpicking', i.e., hitting the contraption with a rock much larger than anticipated by whoever designed the thing, and smashing it to smithereens.