Are you wanting to collect nonsport or gaming (booster packs are really only gaming cards, which is why I am asking)? I know nothing about gaming cards. What's in fashion for nonsport is that there are basically two types of sets - autos/memorabilia oriented and sketch card oriented.
The autos/memorabilia are essentially for television or movie products and I would recommend collecting a show you like since who wants autos of people they don't care about - there's good selections if you like scifi/fantasy. There's a few group buys coming up if you are interested in Game of Thrones, Fringe, NCIS or True Blood. The sketch card sets are generally comics (especially Marvel) with a few others such as Star Wars. These have a hand drawn sketch card in each box. Both types of sets will have a base set (eg episode summaries for TV shows) and various chase sets that are foil or otherwise special cards.