Cheapest? They've worked pretty hard to obscure that. There are so many special discounts, pricing plans, options, etc., that it is almost impossible to say definitively one costs more. The best thing to do is:
1. List which channels you watch most frequently and/or "can't live without".
2. Determine just how fast you need your internet connection to be. Most people can live without the enhanced speeds, especially if they aren't doing online gaming or streaming HD movies. If you need that extra speed add it to your list.
3. Take your needs list and price it for your local cable company, then against what satelite promotions exist in your area. See which one is cheaper at meeting your needs list.
4. When you order, don't let the sales person on the phone "up sell" you into additional packages that aren't on your list. That is where you'll really save cost on your bill.