In the last post, we gave you three of Cramer’s drilling stocks to own: Schlumberger, National Oilwell Varco and GlobalSantaFe. Any or all are good buys because they are either undervalued, open to mergers or at the center of a monopoly that stands to win big as major oil companies look to grow their reserves.

But still, these aren’t Cramer’s favorites. Any regular watcher of the show could probably guess who tops this list of oil plays. Jim has been bullish on these stocks for a while, and his charitable trust owns both: Halliburton and Transocean.

The media has been giving Halliburton grief for its decision to move operations to Dubai, but Cramer says this is a key move for the company because it has been losing business to Schlumberger. HAL’s associations with the Bush administration have cost the company money. But there’s another reason to buy in: Cramer expects the stock to jump because of its tender offer to let you sell your stock in exchange for its recent spin-off, KBR. Hold on to HAL, he says, because this is the event Cramer was counting on when he made it one of his value stocks of 2007.

Best in breed, though, is Transocean. Big oil needs to drill deep, and RIG’s the best offshore contract driller around. Also, the company’s day rates – the amount of money they get per rig per day – are skyrocketing. Then there’s the consolidation we mentioned before. Cramer thinks it is imminent in this industry, and RIG could be acquired.

Another great reason to buy RIG is that this week is when all the options expire. Almost every options-expiration week has led to downward pressure on the stock. Cramer theorizes it is because so many people expect something big to happen that they buy calls on RIG, and then when nothing happens they sell those calls all week long because otherwise they’d have to own the common stock. That drives RIG down to $75 – right where Cramer would buy it.

How do you approach the oil patch? Do the homework, listen to Chevron tomorrow and ConocoPhillips on Thursday, because Cramer thinks they’ll be just like Exxon and Petroleos Mexicanos. Then get ready to pull the trigger on RIG while it’s marked down on Friday.

Questions? Comments?