Enjoy the things that I enjoy. Toodles.
For e-lo’s anon.
Triumphant will get you the biggest bang for your buck. Great primes. Yanmega, Magnezone, Mew, and Electrode is starting to get play as well in decks like Cobalion/Kyreum. Junk Arm is a staple and Twins is a great supporter for slower decks. Also, sharpedo is a lulzy card that can be used with Fliptini.
HG/SS is great to start with because it has DCE, Collector, Communication, and if you’re looking to run reshiphlo you can find Typhlosion prime and ability ninetales there, as well as feraligatr for Kyreum decks, it also has Donphan prime. And you’ll get all the babies, pichu, cleffa, and tyrogue.
Unleashed is a good set as well, you’ll find Shaymin and floatzel which can fuel kyreum decks as well. Blastoise is there also, but given the current meta being Zekrom heavy, its not the best play. You can also get Rare candies in this set. Judge, super scoop up, plus power are also here. Some decent primes: Kingdra and Tyranitar, not really any big player primes in this set right now. Also, Jirachi.
Undaunted is pretty fucking shitty. Vileplume, Weavile, RDL are the only things really worth naming. Vileplume is pretty big right now, and the set has one of the best supporters in Sage’s Training.
Call of Legends is the worst set of them all. It is a set comprised mostly of reprints. Pachirisu would the only card worth mentioning that isn’t a reprint.
Black and White isn’t a great set, but it has Zekrom and Reshiram. Zoroark is here and it is a pretty good card. Ability Emboar can also be used. Reuniclus is in this set as well and can be used to help tank in slow decks like The Truth or in Gothitelle (EP). Cincinno is a decent card, and there are some okay items, Juniper is a nice supporter as well.
Emerging Powers another not so great set. Tornadus and Thundurus are probably the best cards you’ll find pokemon wise. Gothitelle is here, but it isn’t used much anymore. What this set has working for it is that it has the most important card in the format. Pokemon Catcher. It also has Cheren, good supporter.
Noble Victories is a pretty good set. It really opened the doors for a lot of decks. Eelektrik, fliptini, vanilluxe, kyurem, chandelure, Coballion, durrant, terrakion. all big cards right now. Great items and supporters too like Eviolite, rocky helmet, N, Super Rod.
There you are. It really depends on what kind of deck you want to build. Bulbapedia is a great resource. This is a brief rundown really.