Which Oil & Natural Gas ETFs to invest in?

[NeverEnough]

Sold my MRO stocks & removed the funds from 1 of my Int'l ETFs (Didn't need 2 Int'ls)

Looking to put this money into Oil and/or Ntural Gas ETFs, but not sure which (if any)
This $ is 1 of my IRAs so it's not play $.

Here are some that I have on my watch list:

PowerShares DB Oil Fund (ETF)DBO
ProShares Ultra DJ-UBS Crude OilUCO
United States Oil Fund LP (ETF)USO
iPath S&P GSCI Crude Oil Total ReturnOIL
Powershares DB Crude Oil Double Short ETNDTO
United States Natural Gas Fund, LPUNG
First Trust ISE Revere Natural Gas (ETF)FCG
SPDR S&P Oil & Gas Explore & Prod. (ETF)XOP
iShares Dow Jones US Oil & Gas Exp.(ETF)IEO
SPDR S&P Oil & Gas Equipt & Servs. (ETF)XES
PowerShares Dynamic Oil & Gas Serv (ETF)PXJ
ProShares Ultra Oil & Gas (ETF)DIG
PowerShares DB Crude Oil Long ETNOLO

[frenk]

best of luck have good business

[megancheung]

I am pretty much convinced that sticking with low-cost index funds are the best route, compared to actively managed funds. That should weed out a few of those on your list. IEO looks to be a good indexed fund and the expenses are reasonable.

Some, like the Powershares UCO fund, use leverage to try and double the performance of the index. On a daily basis, it's going to gain/lose twice as much as a similar non-leveraged fund. In the long run, these leveraged funds usually don't track their index very well, since fluctuations compound quickly and throw them way off course.