^Kush itself is a term for a group of strains named after the Hindu Kush mountain range. There's lots of strains called kush (Hindu Kush, OG Kush, Bubba Kush, etc.) They're mostly indica.
I know that you just mean weed when you say kush though. I'm partial to White Widow, pineapple kush, northern lights and I love really strong indica strains like most kush strains. I also like stuff with old school mexican and central american genetics.
I think a lot of modern schwag from Mexico and Colombia is grown with the descendents of strains like Panama Red, Colombian Gold and Acupulco Gold, it comes out more when you grow it from seed though because the traffickers drastically reduce the potency of the weed by mishandling it.
There's a thread for strain discussion if you want to see lots of pages of opinions, just use the search bar in the forum. Basically weed strains are either indica, sativa, or a mix. Indica has a more sedating, chilled out and strong body high feeling. Sativa is more energetic and cerebral. I like all weed, but some is better for particular occasions.
I like sativa or hash for before I do stuff, and indica for every other time. But I smoke what I have for all occasions, which is usually schwag or some dank indica. Weed is weed, all of it gets you stoned. White Widow is my favorite strain of the ones I've tried because it's crazy strong and I just love the high.