These are the teams I used on the original playthroughs of the Generation 3 games.

Ruby

Sceptile
Altaria
Manectric
Camerupt
Wailord
Dusclops

Sapphire

Blaziken
Tropius
Manectric
Walrein
Banette
Claydol

Emerald

Swampert
Swellow
Manectric
Torkoal
Seviper
Flygon

FireRed

Blastoise
Pidgeot
Raichu
Arcanine
Arbok
Dragonite

LeafGreen

Charizard
Pidgeot
Raichu
Lapras
Victreebel
Marowak

Colosseum

Espeon
Umbreon
Feraligatr
Ampharos
Noctowl
Magcargo


XD: Gale of Darkness

Jolteon
Cloyster
Ninetales
Sandslash
Ariados
Fearow

These are the most unusual teams that I have used during a playthrough of Gen 3

Ruby

Sceptile
Crobat
Minun
Ninetales
Corsola
Claydol

Sapphire

Blaziken
Pelliper
Plusle
Girafarig
Cacturne
Aggron

Emerald

Swampert
Skarmory
Raichu
Magcargo
Beautifly
Hariyama

FireRed

Venusaur
Dodrio
Electabuzz
Dugtrio
Flareon
Gengar

LeafGreen

Charizard
Magneton
Starmie
Muk
Golem
Beedrill

Colosseum

Espeon
Misdreavus
Jumpluff
Qwilfish
Plusle
Skarmory

XD: Gale of Darkness

Flareon
Walrein
Electrode
Xatu
Forretress
Breloom

What were your best teams and most unusual teams in Gen 3.

Probably the team I used when I didn't play Gen 3. :p

Nah, probably my Dark monotype:
- Houndoom
- Mightyena
- Shiftry
- Crawdaunt
- Absol
- Sableye

Nothing special and honestly I'm not 100% sure if Houndoom was there or if it was an Umbreon that I got from Colosseum.

I still remember my Sapphire original team:


Some of the weirdest were in the randomized runs. Like my team in Fire Red:


Or during Challenges events. For example, my 2014 Challeggs team in Sapphire:

I played R, S, and E, each once. That was a very long time ago, and I didn't use to keep track of my final teams back then.

I do remember most of the Pokémon I had across those three playthroughs, but I don't recall which belonged to which team specifically:

Sceptile, Blaziken, Swampert, Mightyena, Swalot, Swellow, Torkoal, Weezing, Donphan, Seviper, Lunatone, Ninetales... and I can't remember the remaining six.

Obviously the starters were each on a different team, same for Pokémon with overlapping types such as Swalot, Weezing and Seviper, or Torkoal and Ninetales.

As for Leaf Green (my only playthrough on official Gen 3 Kanto) Nidoqueen is the only one I remember.

The most unusual Gen 3 team I ever had was probably my Sapphire team from a couple of years ago, the team that was decided by the Pokemon cards. I didn't know what team to use for this playthrough and I had a few unopened packs of Pokemon TCG cards from the few most recent sets at the time so I decided to open them and use the first 6 fully evolved Pokemon I pull from the packs, first 6 that are catchable in Hoenn of course. So my team ended up being:

- Masquerain
- Sableye
- Magcargo
- Heracross
- Tropius
- Relicanth

Weird team but it made for a very fun and challenging playthrough. Beating the first half of the game with just Masquerain and Sableye was an interesting experience. And then in the E4 and Steven fight it was Heracross that helped me win because the rest of my team was just too weak and/or too underleveled to do any significant damage to Steven's Pokemon.

These two runs in Ruby will forever be my most unusual:

- Plusle and Minun
- Volbeat and Illumise

I didn't use anything else and relied on just these two to beat the game. Tougher, but also a lot of fun!

I often did solo runs with Swampert back when Emerald was my only game. My best team for Hoenn has to be my most recent, from about 5 years ago:

I'd literally never caught a Feebas before, so that was very rewarding. I had to wait until the post-game to blend with Berry Master in order to evolve it. During the story I also used Absol - a great design let down by his stats and typing being at odds - and Clamperl, the latter because when I caught one in a Dive Ball it turned out to have great IVs and Hidden Power Grass, which made it brilliant against Juan and Wallace. Its now in Gen V as a Gorebyss with Shell Smash. Torchic was my first ever starter, and I remember thinking Blaze Kick was incredibly cool, but I'd only ever completed the game with Swampert until then (still never even evolved a Sceptile).
The five pictured (except Clamperl) each reached Master Rank in contests, as well as doing quite well in Battle Frontier (I think I may have beat the Dome Ace): Cool, Cute, Smart, Tough, and Beauty respectively.

I did a LeafGreen run with Red's team from PokéSpe which was quite cool, but not particularly challenging - Venusaur, Pikachu, Poliwrath, Gyarados, Snorlax, and Eevee then Aerodactyl is not exactly a weak team. Now Gold in HeartGold on the other hand...that was tricky! No Fly, for authenticity I didn't evolve Aipom (and couldn't Togetic), not a single super-effective move to hit Dragon (although Sudowoodo could get a hit in on Charizard)...might do it again in the VC release!

My randomized FireRed run was also extremely weird.