Definitions:

• cults: headed by a charismatic leader, not necessarily bad (distinguish between "harmless" and "doomsday" cults)

• sects: a breakaway group, separated out from the mainstream, tend to be relatively small

• denominations: a subdivision within a larger group
  

Examples:

• Western variants of Eastern religions (Martial Arts, meditation [TM, Zen, Yoga], Sufi Order of the West, ISKCON, Theosophy, Eastern Gurus [Sai Baba, etc.])

• Spiritualized, liberal Christian based movements (New Thought, Christian Science, Religious Science, Unity, Science of Mind)

• So called "cults" (Scientology, UFO cults, Jim Jones [People’s Temple], David Koresh [Branch Davidians]) - good or bad in "the eye of the beholder"

• New Age Spiritual Technologies (crystals, holistic healing, spiritualism, channeling, psychic phenomena)

• Neo-Paganism: a return to ancient, earth centered spirituality (Wicca, etc.)
  "Pagan" originally meant "people of the country" (country folk) referring to those people of pre-Christian, ancient Europe who worshipped many gods and goddesses (e.g., Greek and Roman) and celebrated the sacredness of earth and sky, cycles of the harvest, moon and sun ("nature" or "earth based" religions). The term "pagan" came to mean "non-Christian", especially polytheistic and nature religions. The term has taken on a negative connotation and is often extended to refer to any non-Christian, including atheists. But this is a corruption and biased use of the term. True pagans are religious in their own way.