As ballenger pointed out, the type of policy you choose to purchase depends on what your goals are. Whole and Universal Policies build cash value while Term policies don't. The cash value accrues and can either be used to purchase additional insurance or used in the form of a loan.
Term policies are less expensive because they run out at when the term is up (hence the name). Most are renewable without proving insurability; however you will be purchasing the same policy at your new
attained age. So if you buy a 10 year term at the age of 43, at age 53 you can renew it without having to undergo a new underwriting process. But you're now purchasing it as a 53 year old person so the cost will be higher.
Term policies give you more bang for you buck but just remember that you have to plan what you'll do when it runs out. Some term policies are convertible; meaning they can be converted to a permanent policy without proving insurabilty.
One thing I will advise, don't necessarily go with the company that offers you the cheapest rate. Check the financial soundness before making a decision because the worst thing that could happen is that you pay for a policy and the company goes belly up and isn't able to pay a claim to your family.
Here's a site that will be helpful for you to check the fiscal strength of the companies you are comparing:
TheStreet.com Insurance Company Safety Screener | TheStreet.com