Liquid Armor
Boulder Trainer
I really want the saving money with your mother to come back. Loved the random stuff she bought for me.
I don't know if this would count as an old feature or not, but if it is, then I'd really like to see them keep the old color schemes. I loved how the world just felt and looked dark, compared to how in newer games they have been making the world bright and sunny. I just liked how the graphics gave it a dark look.
-Headbutt > Sweet Honey. I agree with Ellie, giving an okay move a field move. Headbutt is cheaper, and faster too, plus sometimes the Pokemon that fell out of the tree was asleep.
-Aprikorns, one of the better suprises in GSC. In HGSS, Kurt should call when they are done, otherwise I forget, like I did 90% of the time.
-Bug Catching Contest = Win
-Odd Egg. Although I never played Crystal, I would love to experience it in HGSS.
-Radio Stations. I liked to listen to the Radio sometimes in GSC, and I will do it again in SS.
-Shiny Gyarados in Lake Of Rage. I know Wi-Fi will be spammed with Shiny Gyarados, but I really don't care.
-A lot of the time based events, like the people that give certain items on certain days.
-That house in Viridian where you could battle the kid once a day that had all three Johto starters.
-Bill giving a free Eevee. I never used it GSC, but I plan on using it in SS.
-The Kimono Girls battle house. I don't know why I liked that, I guess I just liked to guess what Kimono girl had which Eeveelution.
More will be added later.