There are different websites for different kind of products. You can Google for the comparison. You will surely get satisfying answers.
An example of a comparison site is credit card comparison sites. you enter in all your information (name, birthdate, address, SS) and based on your credit score they are able to come up with and compare the best credit card for you
It would depend on what you are wanting to compare.
Nearly every price comparison website such as moneysupermarket.com, comparethemarket.com and confused.com will have a mobile phones section. These will allow you to compare tariffs and prices to find the best deal for you.
To compare student loans you should visit FinAid as it mentions what a good comparison website should offer and it also has a list of good comparison websites.
Regarding wedding insurance comparison websites for the United Kingdom one might check for example "Moneysupermarket". Another option is for sure the page "Compare Wedding Insurance".
You can compare car insurance at websites such as Iselect or Bankrate. Alternatively, you can visit the website of a broker who can give you a comparison of the rates.
One can find information on insurance for students through websites of insurance companies, student services websites of universities or colleges, and through insurance comparison websites. Additionally, speaking with a local insurance agent can provide personalized guidance on the types of insurance students may need.
The car website gave me a side-by-side comparison.
A good comparison website is BizRate. BizRate is by far the most popular comparison website. Other competitive comparison websites include NexTag and shopLocal.
There are a few good websites to compare rental cars for business travelers. A good website for car rental comparison is kayak.com/rentalcars. This website has a five star rating.
There are many website where one could compare IRA brokers. One could check website such as "Fool" for information regarding the comparison of IRA brokers.
Brighthand.com will allow the consumer to do a search and comparison of HTC smartphones. Another website in which you can compare HTC smartphones would be the htc.com website.