SS1 vs SS2

[SoDakJak]

Yes, I play strictly Hold 'Em, and almost exclusively online (I make a trip to Canterbury Card Room in the Twin Cities once every couple of months). If not Super System, then what other books would you recommend. I do not believe any of the books on tells would help me much as I rarely play live. Some books I have been thinking about:

1. Gambling Theory and Other Topics
2. The Poker Essay books
3. ITH by Hilger
4. Complete Book of Hold Em Poker by Gary Carson (it seems to be referenced a lot in SSH)
5. Middle Limit Hold Em Poker by Ciafonne
6. Hold 'Em Poker (do I need this if I have read the other more advanced books (I have a copy of the hand rankings already))

Let me know if any of these books are something that I should buy (and even more if any of them aren't worth my time....) or if you have any other recommended books I shouldn't be without.
~SoDak