My latest run with Pokemon Red got me to bring together a team of 'veterans' and newbies, since I had 5 Gens of experience this time around.
* Charizard (Veteran): My favorite starter of all time, Fire-Flying type, and great for having Fly on hand.
* Nidoking (Newbie): Always wanted to have him in a team, but never got around to him in the old days. A strong Poison-Ground type, with Strength and a lot of heavy physical attacks.
* Raichu (Veteran): I just love Raichu, and I always tend to use it in any Gen 1 playthrough. A very speedy Electric type and great for some flashy sweeping.
* Parasect (Veteran): One word: Spore. Yep, this Grass-Bug type is easy to get early on and makes catching Pokemon a breeze.
* Lapras (Newbie): I always had Lapras around, but I never included it in any of my teams. A solid Water-Ice type, good for Surf (naturally), and very flexible with move sets.
* Mew (Newbie): Mew officially became one of my favorite Pokemon of all time because it is a beast in battles. A legendary Psychic type (completely OP in Gen 1) and its unique move sets make it a joy to have on the team.