Recent discussion of "broken" or unfair cards in EDH has made me realize that it's time for an actual thread here on the nature of disruption in EDH.
Obliterate, Time Stretch, Tooth and Nail, Eye of the Storm.... All of these cards fall into the same catagory. They're combo pieces and yes, it's possible to combo out in EDH. Harder than in 462 magic, but still not really difficult per se. If you don't like losing to combos, you must be a responsible deckbuilder and play reasonable amounts of decent disruption. Stop skimping and hoping that other people will be nice and not kill you... or that one of the other players will save you.
People are slowly learning the importance of having at least 2-3 good graveyard hate cards in every EDH deck... (maybe 1-2 if your meta is somehow light on recursion), but spell disuption is key too. If you don't play any permission, discard or library disruption then don't whine when your opponent takes advantage of your lack of preparation. Even white and green have some good disruption if you use artifacts or look closely.
Moreover, scale your disruption appropriately to the format. Thoughtsieze and Duress are great in 462 competetive magic because the key turns involve spells costing 3-4 mana and one opponent. In EDH they're kinda weak... but there's a whole world of cards which get a lot better in a format which has:
* 6-7 mana win conditions
* Multiple opponents
* more time
My personal favourite is Jester's Cap... it's not exciting but I play one in every EDH deck that I can. I have NEVER felt that it was a dead card and I'm rarely unhappy to draw it (Ok, there was one time where I capped myself for three lands to help improve my chances of topdecking an out... but that's still not TOO bad in an otherwise horrible situation).
Other goodies:
* Nightmare Void -- My flatmate says I have an unhealthy affection for this card but the first salvo is usally put to good use and thereafter it's the perfect dredge card... you only draw it when you need it.
* Cabal Conditioning -- 7 mana is downright reasonable for a spell which, at the very least, usually hits just the badguys for at least 3. Extra points because it can hit non-opponents too in a pinch (See: Pentagram format).
* Draining Whelk -- Another personal fav that I've been promoting since it came out. Sure, there's lots of options for permission out there but if your personal play style disagrees with counters in general the flavour on this bad girl will usually let you play it safe, guilt free

It's also a very political counterspell... if you're feeling vindictive you hit the person who was threatening you in the first place... if you're feeling diplomatic you hit someone else and spread the love around.
* Voidmage Husher -- This one someone else pointed out to me. It's remarkable how often you can trip someone up with this if you're paying attention. Very versatile, well costed.
* Spellburst -- Obvious, but needs to be said. It's a splashable hard counter. True, most EDH threats are expensive, but they're still usually in the 5-8 mana range... and most EDH games you'll have 11 mana with which to counter that Tooth and Nail and buy it back to boot.
Options for "the other colours":
* Ghostway -- Fact is, this card sucks pretty bad in most magic formats... certainly far more than people give it credit for. In EDH though, board wipers are far more common and the cost of restablishing your board is far higher, making this a worthy play. The Highlander nature of hte format makes it even better... they'll never see it comin (and keeping 3 mana up won't rouse anyone's suspicions either). If someone in your meta is abusing Haups like I do, follow The Way... the look on their face will be priceless.
* Imperial Mask, Illumination -- I mention these not because they're great, but because they're white. Masks are surprisingly good at making people "play fair" and at least kill you by attacking. Illumination is a lot better in EDH than many people realize: Disks, Deeds, Eyes of the storm, Isochron Scepters, Karmic Justice, Sylvan Grove, Karn, Myr Matrix, Darksteel forge... the percentage of really power cards in EDH which are enchantments or artifacts is very high.
* Nullstone Gargoyle, Voidstone Gargoyle, Muse Vessel -- The former two are temporary solutions only, but if your GW Thadlid beats deck is getting manhandled by Teferi et al, they'll buy you some time. Disrupting Scepter effects aren't great as disruption goes; they're usually not specific enough. The Vessel's alternate utility as card advantage makes it worth considering though... unfortunately you still can't generate colours your general doesn't know, even if you steal their lands.
* Possesed portal, Armageddon (et al), Zur's Wierding -- One of the best ways for a non-combo deck to beat a combo deck (or deck with combos in it) is to Just Win Now. Portal is probably the best "I'm winning, so game's over" cards I've ever found... espcially if, perhaps you've got some token generation going on? I heard Green and White are good at that. Wait for someone (you?) to wipe out all the threats on the board then drop possessed portal with Mesa or Sprout swarm available. How rude
And really, that's what it's all about. It's fine to be a "good guy", but if you aren't willing to protect yourself with real defenses, appropriate to the weapons your opponents are wielding... then you've got no grounds to complain about those weapons when you lose.
And now I'll open up the floor for suggestions of other good disruption cards in EDH
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