There are some good strategy-tips in this build, and it's clear that you have spent a good chunk of time writing it, something I appreciate. But I still have to agree with bigfatcow; critical strike on Urgot is kind of useless. Good guide, though!

Oh, I see... Sry!

If you were replying to my comment, sorry for the confusion, I was commenting on the build and not on your first comment. I agree with pretty much everything you had said. :) I actually like your guide quite a bit bigfatcow.

I think you have grossly misunderstood what I was trying to say. Firstly, I never said Acid Hunters dont apply hit passive, I just said they dont apply crit. Also, "passive" has more than one meaning... what i meant in the passive part is the opposite of aggressive, which brings me to my 2nd pt, that I'm not the one underestimating Urgot's early game power, because what I mean is that you should play so much more agressively than harassing once in a while. When I play Urgot I will be getting kills before lvl 6 because I keep harassing ALL THE TIME instead of once in a while as stated in your guide.

Also, I know that CDR is imprtant on Urgot, that was the exact point i was trying to make! This is because your build doesnt have enough CDR, and that was what I was trying to say.
Did I even mention anything about flash or ghost???

Couple of things: Firstly, His Acid Hunters DO apply his passive, it is not only auto-attacks. So their is really no reason to get into auto-attack range. Secondly, He is very dependent on his CDR, which at 30%(I believe) will be able to launch four Acid Hunters for the duration of one Noxian Charge. I can understand grabbing the Great Glyph of Warding runes for MR, but if you are going to do that I would recommend getting a Frozen Heart in your build for its CDR/Mana/Armor/Slow. Its really a perfect item for Urgot.
While it seems a solid build, will test later when I am at home, I think you are under estimating Urgot's early lane game. Going top or mid few champs are able to stop Urgot from pushing the hell out of a lane, which you do have to watch out for ganks since he is slow. I play aggresively and can keep the enemy champ from getting farm, thus getting me easy kills. Even going bottom with a support(Taric, Soraka, etc.) you can easily win the lane.
I agree with you on your team fighting strategy, focus on those squishy carries to take them out of the fight, then the rest is a cake walk.
While flash is good, I prefer Ghost since Urgot is so slow that way you can easily get away if you see a gank coming.
I would also trade in the Infinity Edge, I know the AD is great but Urgot should not need to rely on auto-attacks since his range is horrible, for Last Whisper, since Urgot really benefits from the ArPen.
Thanks.

Firstly, Urgot is extremely extremely dependent on CDR, and you have an underwhelming 15% CDR, which is definitely not making full use of his spamming skills. According to the top Urgot guide found here: http://www.mobafire.com/league-of-legends/build/e-n-d-g-a-m-e-88044, you need at least 25% CDR to hit 4 Acid Hunters within 1 Noxian Corrosive Charge. You definitely need more CDR in this build.

You have 15.99 flat + 0% ArPen. Building armor really shuts Urgot down, and with your non-existent ArPen, I really dun see how you are going to do much damage late game even if you're at 450 AD. Perhaps you could change your Infinity Edge into a Last Whisper. I understand you take IE for weaving, but have u checked out Urgot's attack speed and range? I feel that the range is far too little to warrant such an expensive item while a Last Whisper would serve you so much better late game. I think any good Urgot player knows how vital Armor Pen is for Urgot.

Also, if you're catching up to a fleeing ****, chances are he wont be in 425 range, so you wont be weaving cause your autoattack range sucks big time. Instead, it will be your Acid Hunters, which cant crit, that will be doing the talking.

Also, I really dun see why you play passive until you get your ult. I agree that Urgot's damage at level 1 and 2 probably isnt good, but from level 3 onwards his damage is so high and his harassing power is so good. The thing that defines Urgot in lane is the amount of harassment he can dish out. You confuse me, you did say "spam your abilities to increase your mana", but later on in your guide you say "some harass power now and then". If you're really spamming spells at that guy, it shouldnt be some harass power because the harass power is ridiculous. However, "some harass power now and then" is definitely not going to work in solo top as solo top champions have high sustain, especially since you didnt get an ArPen item like Brutalizer or even ArPen marks. By the time you reach lvl 6 they would be back at full hp, so your little bit of harassment did nothing at all. Instead of playing passive, Urgot should instead play aggressively while remaining safe from his huge range, allowing him to zone out the enemy laner or snag a kill if the enemy makes a mistake pre-6.

Well, this build may have worked well for you perhaps because you are really good at this game but I think that this is not the most optimal way to play him. Even professionals do need Armor Pen.