I built my list based on Mary Jacobson's Top 16 list from GP Atlanta. [brags] It's currently all-foil and the duals are German FBB. The REBs are Beta. [/endbrags]
4
Arid Mesa4
Wooded Foothills3
Windswept Heath2
Plateau2
Taiga1
Savannah1
Mountain1
Forest1
Plains4
Wild Nacatl4
Kird Ape4
Loam Lion3
Grim Lavamancer4
Tarmogoyf4
Qasali Pridemage4
Lightning Bolt4
Chain Lightning4
Path to Exile3
Lightning Helix2
Price of Progress1
Sylvan LibrarySideboard:4
Leyline of Sanctity3
Red Elemental Blast2
Grafdigger's Cage1
Relic of Progenitus2
Krosan Grip1
Ancient Grudge2
Pyroclasm/2 Sulfuric Vortex/1 Lightning Helix, 1 Price of Progress
The last sideboard slot changes based on what I'm expecting more of. Vortex for fields heavy on Stoneblade/other UW decks, Pyroclasm if I'm expecting a decent amount of Goblins/Affinity, an extra Helix and Price if I'm expecting a wider field or a lot of BUG/RUG.
As for the metagame position, I think we are favored vs RUG/BUG: these decks are the reason to play Zoo, our creatures outclass theirs and we have way more removal. You should win any game against these decks that you don't get Wastelanded out.
We are not favored vs combo of basically all flavors, though I think some matchups, like ANT, High Tide, Dredge, and Reanimator are a lot closer than people think. ANT and High Tide usually go off around turn 3-4, giving you plenty of time to race. ANT in particular needs life in order to go off, so if you can knock them down to 10-11 life fairly quickly, they have a hard time not killing themselves. Don't be afraid to sling bolts at the dome as early as you can. High Tide is very slow and easily disrupted with a single Red blast postboard. Dredge is actually a pretty grindy matchup, since they should never be able to get a token from Bridge from Below, since you can almost always kill one of your own guys to get rid of them. This leaves them trying to race you with Ichorids (which you can path or just race, seeing as your guys are faster and you have Helix) or setting up a Dread Return. Reanimator is a matchup I've personally had a lot of luck with lately, so maybe it's just a small sample size bias, but the fact that Reanimate often deals 9-10 damage to them will allow you to steal a lot of wins. One thing I like to do is to sandbag burn when I think they are about to go off and try to burn them out with Griselbrand's ability on the stack (after they are down 7 life but before they have a fresh hand full of counters). TES is very rough but you should be able to steal a few wins. Show and Tell and Belcher are pretty much unwinnable. Your goal is to dodge this deck.
We are fairly even vs Stoneblade/Miracles. Miracles in particular is really not set up to handle a decent amount of reach, especially when you have answers to Counterbalance postboard. I usually get them to 10-12 life with creatures before getting wrathed out, and then burn them out as the game goes long, since I have more Bolts than they have creatures. Stoneblade is usually well-equipped to play a grindy game with us, but as they don't usually have Wraths you can usually remove all of their threats while forcing through a couple of dudes. Batterskull is pretty rough, hence the two Krosan Grips in the board.
I actually think Goblins is much worse of a matchup than it used to be. Krenko in particular gives that deck a way to just crush most board states, and they are usually very well equipped to overload your removal and just chump block your guys forever.
Burn is basically a bye, especially with Leylines in the board. (Which are there primarily for storm, but I chose them over the other options because they provide splash hate for burn and they are resilient to duress/silence while buying you enough turns to win. You don't need to lock a Storm player out completely, you just need to slow him down by a turn or two, i.e. while they find a bounce spell)
Edit: Forgot to talk about Junk and Maverick. These decks are somewhat unfavorable, though not so bad as combo is. Jund has the removal to keep you on the back foot and the clock to stop you from closing out with burn. Maverick can usually shut you down on the ground fairly quickly and take over with a Knight. However, these matchups are basically the only reason to put garbage like Bloodbraid Elf and Knight into your Zoo deck, and I think this narrow section of the field isn't worth it. These decks are built to prey on fair decks like Zoo, and changing your deck to fight them is just going to cause you to become an awkward inbred fair deck that is giving up its only real edge.
As for some of the other lists floating around in this thread, I think Knight and Thalia are absolutely terrible in Zoo. The reasoning is the same that I often saw a few years ago (around the time of GP Providence) for playing stuff like Wasteland in Zoo. The problem is that when you're playing Zoo you really don't care about a lot of the things that normal decks care about. Knight of the Reliquary seems particularly bad to me right now because it eats it very hard to Abrupt Decay and a vanilla 5/5 or whatever just isn't where I want to be spending my mana. At least Woolly Thoctar isn't soft to Deathrite Shaman. Thalia might be slowing down your opponents, but there are often going to be times where you play a Thalia, your opponent plays a Deathrite Shaman and a Bob, and you have a fistful of removal and 2 lands and can't stop your opponent from getting ahead. Thalia hurts us often as much if not more than many opposing blue decks.
As for different versions of Zoo, the "Big Zoo" and "Standard Zoo" described by others, in my mind, are basically just "Bad Jund" and "Bad Maverick", and I subscribe to the "Prime Directive", which is "Never play a bad something else". The reason to play Zoo over another deck is because it's (in most cases) a better burn deck than burn. It's not a better midrange deck than Jund, and it's not a better creature deck than Maverick. You need to be clocking your opponent as hard as possible as consistently as possible and punishing every stumble that you can.
Overall, I agree that Zoo really isn't much of a deck right now, but it has some reasonable matchups, and certainly some amount of format/deck knowledge will often carry the day. I certainly do better playing Zoo than any other deck, just on the basis of how long I've spent playing it.
Re: Price hitting for 6+ damage, I actually have found that it takes a lot of effort to "get" someone with Price, and the times it sits wasted in your hand or your opponent plays around it (which is fairly frequent, if they are competent) are pretty brutal. I think hitting for a consistent 4 with Boros Charm, plus the added utility of that card, make it better. I plan on cutting my 2 Prices for Boros Charms as soon as my foil Charms arrive in the mail. :)