Ah yes, a long history to post. Played so many games. Here we go.
Ruby:
One of the first games I played, I also have Sapphire which I obtained before Ruby but I can't remember the team I had. Swampert is one of my favorite starters, so I picked it, especially because Water-types have the lovely Surf which is awesome. Crobat was there because I felt the need for a Flying-type to handle my rival's starter (Treecko/Grovyle), and having Fly later on was helpful too. Hariyama was a neat member of my team, helping me get around Norman, Glacia, etc. Gardevoir is arguably the best Psychic-type one could ever have in-game (other than Alakazam), and I love Gardevoir. It was tough to train but as soon as I got Gardevoir I had a real powerhouse in my hands. Absol is a personal favorite of mine so I picked that as well, it kinda sucked since it didn't have any good Dark-type moves but SD+Shadow Ball proved itself useful, especially against Phoebe and Tate/Liza. Dusclops is just there lol, though it handles some Pokemon rather well and its bulk proved itself handy in clutch situations, though it was rather passive lol.
Diamond:
I like 4th Gen. Anyways, I picked the Water starter again, as you can see. Empoleon was pretty great, even as a Piplup, and proved itself very useful throughout the game. Having Surf was a nice tool too. Staraptor was the basic bird of DPP and it was pretty useful, especially with Fly, and it was powerful so it was nice to crush opponents. Its design is slick too. Luxray was pretty cool and its Electric-typing was neat, it was pretty decent in-game and I love Luxray, especially for its awesome design. Kadabra was okay even though I never traded it, it still was strong and fast so it made a good member, it was so frail though. Garchomp is awesome and even though as a Gabite it was kinda lackluster it still was cool. Lucario was added late and I got it from the Riolu egg, but it was a useful Pokemon regardless. This game was kinda hard but fun lol.
Black:
This is one of my two BW1 teams. Now I usually go for the Water starter, but this time I went for the Fire starter. Emboar was useful throughout the playthrough, even as Tepig and Pignite, and it gave me a good advantage against Lenora, Burgh, Brycen, and Grimsley. Simisage helped take care of Cress and other Water-types and was decently useful throughout the game (yes, I had the gut to keep my monkey). Gigalith is something I picked simply becuase it's sturdy and strong, and I managed to trade with myself since I have both Black and White as well as a DS Lite and a DSi. Seismitoad was good for being a Water-type and having Surf, and even though most Water-types suck, Seismitoad was good. It also gave me a decent advantage against Elesa as a Palpitoad. Sigilyph provided Fly and was good for being pretty strong. Galvantula sucked as a Joltik but as a Galvantula it was a good member of my team and helped me out of some clutch situations. Galvantula is also cool design wise so yeah. This was a fun game imo.
White:
I got my hands on both Black and White so yeah. I didn't pick the water starter in this game either, I picked Snivy. Serperior was pretty decently useful, it wasn't that strong but it was nice for its typing and it had Coil so that was neat too. Simipour was of nice help against Chili, and it had Surf which is always useful. It's also one of the few Water-types from BW1 in-game that didn't suck (the others were Samurott and Seismitoad). Zebstrika wasn't shabby since it gave me the edge against Skyla and hit decently hard, though having to stick with Spark as STAB until Victory Road kinda sucked. Unfezant is BW's basic bird so I picked it, it has Fly which is always nice, and it was strong too. Krookodile was awesome since it came right before the gym battle with Elesa, and Moxie made it a great team member throughout the game. Escavalier was great because it's strong and durable, I got it because I traded with myself lol.
White 2:
I got my hands on White 2 but not Black 2 lol. This time, I did pick the water starter, and Samurott has always been a neat mon on the team because it's strong and had a lovely movepool including Surf. I picked Stoutland simply to be a well rounded literally 2HKO doge that proved itself decently useful, though it was the least useful member, but it did have Strength and literally 2HKOed things. Crobat was my pick for my Flying-type and was pretty useful, a fast Acrobatics was cool stuff too. Lilligant was chosen to be the Grass-type and having QD made it one of the best members of my team. Magnezone was cool because it was Sturdy and really strong, I loved using Magnezone throughout the game. I have a penchant for Krookodile so it became a part of my team again, and was still awesome. White 2 was an awesome game but it took a really long time to complete lol.
Y:
The most recent game I played, so yeah. I picked the Water starter again, Greninja is awesome and was a cool member of the team; it had Surf too. Its sick Speed always came in handy as well. Talonflame wasn't bad and is XY's basic bird so I picked it for Fly and in general being able to cover Greninja rather well. I was looking for a Fairy and I didn't want to bother with Florges or Sylveon so I went with Gardevoir, like in Ruby it was tough to train but gave awesome payoffs. As for the Kanto starter from Sycamore, I went with Venusaur simply because I already had Talonflame and Greninja, and Venusaur was great, especially Mega Venusaur. I picked up a Honedge, and all throughout the game Aegislash has been great. Aegislash was clutch for its typing. Lastly, I used a Tyrantrum simply because it's decent and it was strong too, while giving me a decent edge against Clemont. This game was rather short but enjoyable.
Yeah, a long history here lol. I'm a really devoted Pokemon fan.