I don't really watch reality TV much, but the ones I like are the ones with more of a point:

• The Colony
• Sister Wives
• Jesse Ventura's Conspiracy Theory
• Life After People (does future-reality count?)
• Taboo
• Those weird-mystery-illness shows on Discovery Health
• That series of BBC documentaries with the reporter who gets really thin or botoxed-up or whatever
• ..this list was really hard to make, because I don't watch much reality.