Hilo is an okay town. When people think of paradise they think of Hawaii, or vice-versa. Usually they are thinking Waikiki Beach, Kona side, or parts of Maui. Those places don't get 120+ inches of rain a year, so make sure you don't bring anything to Hawaii that you want to stay in pristine condition.
What Hilo isn't: a vibrant city with tons of events, shopping, and other entertainment. There are cultural events i.e. Local culture, Western and Eastern, but you have to keep in touch via paper to find out about them. I am not a browsing shopper, so there are a few stores here that might satisfy but if you need something go to Amazon or some other online retailer, if you get free shipping you will be skipping the extra 50% mark-up that products receive here. And restaurants close around 9 pm if you are lucky, earlier if you aren't. Ken's Pancake house is open 24/7 except one Tuesday a month if you need it.
What Hilo is: A small sleepy town growing up from being a sugar plantation center to something of a tourist base. Through the last five years even it has gotten a bit better, or my standards have dropped. While the town itself is not really a tourist destination there is Volcano National Park about 30 minutes out of town, and the Telescopes on Mauna Kea. As well as a few beaches... not the pristine white ones! Black sand and rocky beaches abound on this side of the island with a few good snorkeling spots. And you can watch whales from approximately December to March.
Oh and did I mention it rains quite a bit?