Mid/Top.
Becomes a great duelist, gank happy machine.
Jungle.
No one expects how strong teemo really is in jungle, spam shrooms at the other junglers entrances/exits of his jungle, gaps into lanes, and dragon/baron pits to control the jungle. Blood razor + fm + hurricane is so dirty, slow, hp%, and damage, plus the heal from Hextech gunblade procs on your poison and hurricane bolts, massive heals.
Mid.
Ap Nasus is sleeper op. (Not really so dont flame, just hurts ALOT in lane). Once you get lichbane and rush a rylies, then go for spirit visage, thne either hextech or hourglass, you can sub the hextech out for a Abyssal scepter if you need more AP n MR, but the gunblade gives you so much heals from the damage around your ult, and E.
Edit: Adding couple more for other roles.
Support.
.
Theres alot of items that can work on him, the only ones that are a must, are boots, locket, zz, and a SS item (targon is good cause your melee and the heals are nice since you will trade with your Q). Panth has one of the highest movespeeds (if not the highest?) in the game, and one of the best trading kits ever, he curb stomps most other melee champs, which are tank supports, with his Q, he can HARD trade with your ADC vs the other ADC, and if they get minion aggro, you can W to stun, E for damage, and Q when they run, and best part, you can ult in back to lane to save your tower/gank a lane with jungler.
Jungle. (BUT WAIT, THERES MORE!).
So much movespeed, so much damage, so much utility, you will make them cry.
ADC.(ish)
.
Now i know this isnt a ADC, or ranged, but the whole ideal of him is to hard push and farm up and stall out bot lane for the jungler. If he has a good support who can chain CC with his Wall or set it up for him, their dead, end of story, works well with,
but even better with ranged supports who can harass for him,
, and still lock down champs.
Top.
Whole point of this guy, is to facetank, and heal, and tank some more, and heal some more, and kill any
. You WILL out heal his Q blows.
Jungle.
or
His early game sucks dick till you get your ult. But once you do, no lane, or jungler is safe from you. You will blow anyone up from any angle, period. The RoA is a must, as your Ult cost goes up, so does the HP you get back from it does as well. Which would make
a good item to replace Echos with if you want to trade damage for more hp, cdr, and mr (plus heals).
Mid.
.
or
.
HERE COMES THE BOOM.
Top (most trolling, cringe worthy, out of all of these.)
Everything about this build, is to live, and throw down more heals, and do bullshit to your enemies, i recently saw a plat 5 player, destroy a plat 3 darius with this build, it was hilarious, he went 6-0-3 in lane, their enemy lee and darius tried to turret dive several times, and failed obviously.
Jungle.(BUT WAIT!)
Max your Phoenix Stance, the R, and your E, Bear Stance, for max speed, this is ALL about wave clear, and split pushing, and destroying, turrets as fast as possible, all i see anymore are Godyrs who go ad or full tank and try to dive and do stupid shit. Just do this, and split push, all day.