Here are a few things you should know before looking at my team:
☆I don't like legendary Pokemon for my perma-team (and I'm sure you don't, too)
☆I only choose 5 Pokemon 'cuz my 6th will either be an HM-slave, or the Pokemon I'm raising when fighting the E4
☆I don't use Pokemon who can only be acquired through trading with other players
☆I try to include all HMs
☆I try to cover all types
I chose Fennekin as my starter, 'cuz my brother already chose Frog Ninja and, SPOILERS, I hear you can get Shauna's starter in-game (which is Chespin, in this case). Since Fire-type is my favorite type, I also thought having a Fire-Psychic starter would be awesome (if you don't mind the fact that Delphox looks like a female even though mine is male).
Delphox w/ Amulet Coin
Type: Fire | Psychic
Solar Beam / Grass Knot
I have a tendency to give the Amulet Coin to my starter Pokemon in every game. Delphox is a offense-focused Pokemon with very high Sp. Atk and Speed. Flamethrower and Psychic are both strong STAB moves, so it's a no-brainer. Shadow Ball is a great choice, since Delphox has very high Sp. Atk. Solar Beam / Grass Knot is for type coverage and a way to fight the common Water, Ground, and Rock types. I use Solar Beam 'cuz of its high damage and, since this is an in-game team only, the 1st turn won't bother me that much 'cuz I almost always have higher-leveled Pokemon than AI trainers.
In-game location: Starter Pokemon
Weak to: Ground | Rock | Ghost | Water | Dark
Resistant to: Fighting | Steel | Fire | Grass | Psychic | Ice | Fairy
Immune to: None
I chose Lucario because this is actually the first time I had the chance to include Lucario in my permanent party, and so I wanted to try him out, and because Fighting-Steel seemed like a great type matchup. Plus he looks really cool~
Lucario w/ Poison Barb
Type: Fighting | Steel
Ability: Inner Focus
I gave him Poison Barb to strengthen his Poison Jab since his Attack is not as high as his Sp. Atk. Lucario is also an offensive-type Pokemon. He has very high Sp. Atk and Attack, and has good Speed. I did not give him Lucarionite because I personally try not to use Mega Evolution as much as possible, but that's up to you. Aura Sphere and Flash Cannon are strong STAB moves, but since Flash Cannon isn't available until post-E4, you could use Metal Claw or Dig (up to you). Dark Pulse and Poison Jab are for type coverage.
In-game location: Route 22 (Riolu)
Weak to: Fighting | Ground | Fire
Resistant to: Normal | Rock | Bug | Steel | Grass | Ice | Dragon | Dark
Immune to: Poison
I chose Sylveon because I wanted to have an Eeveelution in my party, and because I really needed a Fairy-type Pokemon (or at lease a Fairy-type move, which no one in this party can learn, sadly).
Sylveon w/ Quick Claw
Ability: Cute Charm
Last Resort / Giga Impact
Light Screen / Rest
I gave him Quick Claw because Sylveon has very low Speed. Sylveon is my defensive Pokemon. He has very high HP and Sp. Def, and has a very high Sp. Atk than Attack. Moonblast is a very strong STAB move. Light Screen and Reflect are for higher Sp. Def and Defense for my party, but since Sylveon has a high enough Sp. Def, you could use Rest or Draining Kiss instead of Light Screen for HP Recovery. Last Resort / Giga Impact are for strong damage, but you may also use Hyper Beam or Shadow Ball instead if you prefer Special attacks.
In-game Location: Route 10 (Eevee)
Weak to: Poison | Steel
Resistant to: Fighting | Bug | Dark
Immune to: Dragon
I chose Lapras because the nostalgia is real!!! Lapras has been one of my fave Pokemon ever since I've played LeafGreen (my very first Pokemon game). Lorelei's Lapras with its Thunder scared the heck out of me~~~
Lapras w/ Magnet
Type: Water | Ice
Ability: Water Absorb
I made Lapras hold a Magnet because Thunderbolt is the only non-STAB move he has. Lapras is a bit of a tank Pokemon, with his very high HP. He has low Speed, and the others stats are average. Surf and Waterfall are HMs, which is used for outside of battle, and has decent damage. You have a choice of either using Surf for enemies with higher Defense since Surf is a Special move, or Waterfall for enemies with higher Sp. Def since Waterfall is a Physical move. Ice Beam and Thunderbolt are great moves for type coverage.
In-game Location: Given to you in Route 12
Weak to: Fighting | Rock | Grass | Electric
Resistant to: Ice
Immune to: Water (Water Absorb)
I chose Dragonite because I always leave a spot for Flying-Dragon types in my perma-team and Dragonite has been my most favorite Pokemon ever since I've laid my eyes on him. Given the chance, I always put a Dragonite in my party. And he has really decent stats, too.
Dragonite w/ Leftovers
Type: Dragon | Flying
Ability: Inner Focus
Rock Slide / Stone Edge
I gave him Leftovers, because I honestly don't know what else to give him. I guess you could give him an item that increases the power of his moves. Dragonite is a Pokemon with balanced stats, with a main focus on Attack. Dragon-type Pokemon are almost always a good choice because of their resistance against the very common Starter types (Fire, Water, and Grass). Outrage is a strong Dragon-type move, and I just can't imagine a Dragonite without it. Fly is an HM for moving from town to town, and has decent damage. Rock Slide / Stone Edge and Earthquake are strong moves for type coverage. You can either choose Rock Slide with good damage and decent accuracy, or Stone Edge with higher damage, but less accuracy and PP. Your choice~
In-game Location: Route 21 (Good Rod for Dratini, Super Rod for Dragonair)
Weak to: Rock | Ice | Dragon | Fairy
Resistant to: Fighting | Bug | Fire | Water | Grass
Immune to: Ground
My 6th Pokemon is always either an HM-slave, or a Pokemon I'm raising. This game's HM-slave iiiis drum rolls DIGGERSBY!!! applause I mean, really, why do people get Bidoof when you could have a Zigzagoon or Bunnelby with a Pickup ability?
Diggersby w/ no item
Type: Normal | Ground
No item for him because of his ability, Pickup (Pickup is life). Diggersby has fugly stats, but it doesn't really matter. Cut, Strength, and Rock Smash are very important HMs to have when exploring (although Rock Smash isn't an HM anymore, but you get the point). Dig is very useful for escaping caves, and it's also a STAB move with decent damage in case you get into a situation in which you need to use him in battle. I mainly use him as a meat shield for reviving someone else.
In-game Location: Routes 2, 3, 5, and 22 (Bunnelby)
Weak to: Fighting | Water | Grass | Ice (does it matter?)
Resistant to: Poison | Rock (pretty sure it doesn't...)
Immune to: Ghost | Electric (nope, doesn't matter...)
Note: From early to mid-game, before I had Lapras, Eevee, and Dratini, I used Wartortle / Azumarill, Raichu, and Pidgeotto as replacements.