[Zandock]

Thanks for the list. About to start my next run so might as well do a quick run down of my team the first time through

Azurill: - High
Availability: Flocessy Ranch. Very early on, and not too hard to encounter.
Stats: Attack is the reason you raise Azurill. Its speed is nothing to write home about, but it has enough bulk to allow it to hit back hard with huge power.
Typing: Pure water is pretty great. There's not too much that resists you or hits super effectively after Nimbasa
Movepool: Aqua Tail and Return are all you'll need for a good while, as it offers perfect coverage in-game. Rollout + Defense Curl can even be helpful early on. Super Power and Ice Punch are good options later on. Or just stock up on HMs if want.
Major Battles: Nothing special against the first two gyms, though Return can do work if you aren't stingy with potions or do some walking around. Burgh and Elesa don't give much of a chance to shine, though you can use it against Burgh's Dwebble at least. Clay is a clean sweep. And you can Ice Punch through most of Skyla (Or even Rollout if you still have it for some reason) if you don't have an Electric type. Drayden is susceptible to Ice Punch once again. You can trade neutral hits with Marlon fairly easily, but Jellicent stops you cold.

Does fine against most of Plasma, including Zinzolin, just powering though with Aqua Tail. Not much help against Corless, though. Superpower can helm against Grimsly, but isn't of much particular help against the E4. Ice Punch is as useful as ever against Iris.
Additional Comments: If you don't mind taking the time to get Azurill past the baby stage it will serve you well throughout the whole game. Highly recommend spending 10 Shards to get Ice Punch. Mine wound up with Waterfall/Ice Punch/Super Power/Surf. But you could even replace Super Power with Strength to have an HM slave who still wrecks things.

Riolu - Mid
Availability: Flocessy ranch, almost immediately. Rare
Stats: Lucario winds up with great stats where they matter. Attack, Special Attack, and enough speed for in-game. Defenses are enough to live a hit or two with his typing.
Typing: Steel is great as usual for resists. Fighting STAB is great as always.
Movepool: This is what stops Lucario from being High in my opinion. Being stuck with Force Palm for so long is just painful. Return is great, but it's hardly exclusive to him. I don't have the patience to grind BP so Brick Break was out of reach. Bone Rush/Dig can offer a little more coverage. Dark Pulse was a great boon for me. Winding up with Calm Mind and Aura sphere made it all worth it in the end.
Major Battles: If you do some grinding Force Palm will walk all over Cheren. Otherwise Counter works fine too. Grinding Happiness makes Roxie a breeze if you manage to evolve. Rock Tomb can be used to plow through Burgh. But Return is just as good against everything but Dwebble if you have enough happiness to evolve. Isn't particularly great against the rest of the gyms, and probably a bad idea against Clay. Absolutely wrecks 3/4 the E4 with Calm Mind, Dark Pulse and Aura Sphere, only having to sit out against Marshal. Can do plenty against Iris once you get past Hydreigon's flamethrower.

Resists just about all of Team Rocket's attacks, and makes quick work of Zinzolin and Corless. Set up six Calm Minds against Ghetsis' Cofragrigus and swept his whole team.
Additional Comments: The most painful part about Lucario is Force Palm and some time babying or just running up and down for a little while. Going with Swords Dance might also be useful, but I had a lot of success with Calm Mind.

Trapinch - Low
Availability: Desert Resort, before the 4th gym, rare.
Stats: Pretty disappointing at every stage. Trapinch has great attack, but is so slow and frail you can hardly use it. Vibrava is still frail, and actually loses attack. Flygon is fairly well rounded, but after all the work you go through, it just doesn't seem worth it for only middling attack and "okay" bulk.
Typing: Ground isn't a bad typing for when you get it. Dragon/Ground is very nice with its resistances.
Movepool: You're stuck with Dig all the way through. Rock Slide is an early saving grace. Dragon Claw is a looong way off for a usable second stab, and no Outrage hurts. A few coverage moves like Crunch or Fire Punch are okay. Fly gives it utility and something to hit grass, bug, and fighting types with.
Major Battles: Trapinch is Top Tier for the gym battle right after you catch it. It walks all over Elesa with Dig and Rockslide for Emolga. You might want an Eviolite on it to make sure you survive Zebstrika's Flame Charge.
If you manage to evolve it before Clay, Sandslash can't hurt it too badly and Dig is okay against Excadrill. Rock Slide can be used against Skyla. Drayden will walk all over you. Doesn't have much to do against Marlon, either. Not much special against the E4. Crunch might be good against Caitlyn and Shauntaul, and Fly is okay against Marshal. Dragon Claw won't take out the Champ's dragons and they'll OHKO you back.

Zinzolin will take you out with Ice Beam. Dig is useful against Corless at least. Can help out against Ghetsis's poison types.
Additional Comments: The amount of babying you have to do for such a small payoff just wasn't worth it to me. Trapinch and Vibrava took loads of damage, even with Eviolite on. And Flygon just doesn't hit all too hard.

Litwick - High
Availability: Celestial Towe, just before Gym 6. Very common
Stats: Poor as a Litwick, but amazing as a Chandelure. Skyhigh special attack, with enough speed to get over some things, and okay bulk.
Typing: Ghost is always a great typing for switching in on fighting or normal type moves. It does kind of suck how pretty much every fighting type has Dark or Rock type moves, though. Fire typing doesn't grant resistances to many common attacking types late in the game, unfortunately. Ghost and Fire stab is resisted by nothing in-game I can think of.
Movepool: You start off with Flame Burst, WoW, and Hex. Which is good enough to get you through to Reversal Mountain where you upgrade to Shadow Ball. You can get Fire Blast shortly after, but I found that Flame Burst was good enough to use until Flamethrower. You can add on stuff like Energy Ball or Psychic. But really, I never used anything besides my STABs or WoW. Chandelure is just so overpowering with them.
Major Battles: Litwick can put in some work vs Skyla's Swoobat and Skarmory, just keep it away from Swanna. Drayden's pokemon all have Dark moves, but if you burn them you can still fire off super strong Shadow Balls if need be. Marlon's pokemon can be beaten with Energy Ball and Shadow Ball, but it is a little risky. None of Shauntal's pokemon want to take a Shadow Ball. Obviously stay away from Grimsly. Marshall can be a problem too thanks to all the Dark and Rock moves.

Zinzolin and Corles are very fire weak. Chandelure can easily take out Ghetsis's Cofagrigus, and his Palpitoad if you carry Energy Ball.
Additional Comments: The only bad part about Chandelure is Litwick. But it's just a few Audino's away from becoming a Litwick. All the moves you need are TMs, so you can evolve immediately again with the Dusk Stone from the Strange House. Chandelure's Special Attack is just so high it overpowers just about everything you come across.


I also used Mareep and Venipede, but I think their tiering is good where it is.