Sorry about the wait. I've fixed the typo. It allows you to return an SP Pokémon to your hand.
HGSS
2010 was the year of a whole new era, with new types of Pokémon and trainers that would dramatically change play.
They introduced the Prime, a special evolution card with a jagged and shiny border that usually worked well in combination with other cards.
They introduced the LEGEND, which needs both halves to be played at the same time, and has amazing HP and very powerful attacks, the drawback being that you take two prize cards when one is defeated.
They introduced Baby Pokémon with the Sweet Sleeping Face ability, which could work as great starters and each was unique, a key point being that Pichu was the prerelease promo for the set. That meant that every player in a prerelease of HGSS got one special Pichu. Pichu was, and is, an amazing starter if you want to get Pokémon onto the field.
They introduced (or in some cases reintroduced) amazing trainers such as Pokémon Collector, Copycat, Pokémon Communication and Double Colourless Energy. In the current format, you should always run at least one of these cards.
Of all of these cards, there are some stars that have seen a lot of play since their release. I'll run quickly over them.
Feraligatr Prime
Lets you get water energy instantly onto the field from your hand when you use his Poké-Power.
Typhlosion Prime
Lets you recycle discarded Fire energy when you use his Poké-Power, attatch it to a Pokémon, but put one damage counter on them.
Jumpluff
The pioneer of swarms, Jumpluff does more damage for the more Pokémon you have on the bench. Cinccino was introduced this year with a similar attack,and so the work very nicely together. Even before 2011, Jumpluff was winning big competitions alongside Pokemon Collector.
Ninetales
His Poké-Power allows you to discard a Fire energy from your hand and draw 3 cards. This means that he's a perfect partner for Typhlosion, allowing drawpower and also preparing Typhlosion, getting two energy and one damage counter on him each turn. For this, Ninetales is always a useful tech in fire decks.
Donphan Prime
An all-round great card, it'd be surprising if you didn't know what Donphan did. His Exoskeleton takes 20 damage away from any attacks done to him, meaning that most basics that evolve into something can't even touch him. His Earthquake allows 60 damage for one Fighting energy, at the drawback of 10 damage to each of your benched Pokémon. His other attack always does a concrete 90 damage, not affected by anything else, for 3 Fighting energy. When the Arceus set was still legal, he could be paired with Bench Shields that stop one of your Benched Pokémon from being harmed by attacks, and so he could safely do several Earthquakes without harming benched Pokemon you care about.
STORY BREAK
Any more questions?