The simplest answer to this question is that bundling internet and cable typically allows you to save money and time. Using a single company typically means that they are going to offer you a lower overall price than adding on each service individually. You can also enjoy the convenience of having one monthly bill. If you don't want these services, ask if you have the option to build the bundle that you want as some companies may allow for this.
Although not every provider allows for this, some TV internet providers will allow you to bundle a wireless phone plan with an internet or TV package. This may not be available by all providers though. Some internet providers have wireless phone capabilities while others do not. Make sure to look into what options are available for bundling if this is something that you want.
Depending on your geographical location, the price and features of the bundles available is going to vary. For example, some companies may have a lower price but not have the same speeds for internet as other providers. There is likely not one clear winner when it comes to price and performance at the same time. Compare internet speeds along with prices to find the right price point for your budget and needs.
Most of the larger companies such as Xfinity, Frontier, and CenturyLink all offer cable and internet without a contract. Keep in mind that the features are different with each provider and they're not available everywhere. You may end up paying more if you decide to choose a plan that does not have a contract. However, you will have the benefit of being able to cancel your plan anytime which may be ideal for short-term internet needs.
In general, bundling is the best way to enjoy multiple services while paying a lower overall price. Buying individual services is possible but you'll probably pay more with this option. The only downside is that you may end up paying for services that you don't need. Look at the bundling options in your area to determine if you would use everything included. Price out the individual options as well to determine if all of them are needed and you'll find the optimal price point.