KenLiu,
Beyond price, there are a few other factors that can differentiate life insurance companies:
1) Ratings. The financial ratings of the company are extremely important. They are the grounds for determining whether the company will actually still be here to pay the promised life insurance death benefit in the future. Stick with companies that have quality ratings.

2) Service. Of course, service can be hard to judge, but at a minimum, reflect on the service interaction you're getting from whoever you're working with at the company.

3) Product selection. Beyond just the price difference, products themselves can vary by company. Some companies may have term with more attractive options to convert to permanent in the future if necessary, others will not. Depending on what particular product details are important to you, you may find that one company's term offering is a little more attractive than another.

4) Underwriting. If you have any health concerns at all, you may find that different insurance companies view your health issues differently. You may get a preferred rating from one company, and standard from another, or standard from one and an extra-cost "rated" policy from another. Not all companies view a potential insured the same way.

5) Mutual vs. stock. Mutual insurance companies are essentially owned by their policyowners, and to the extent the company has significant profits, they are distributed back to the policyowners as dividends. Stock insurance companies, on the other hand, distribute profits to their stockowners. Some people prefer the opportunity to receive back dividends if the insurance company is successful, and prefer policies from mutual companies. If you're buying from a mutual company though, be certain to verify whether the particular term policy you're purchasing would be a "participating" policy (i.e., eligible for dividends). Not all term policies are participating, just because they're issued by a mutual insurance company.

I hope that helps a little!