Giant Balloons of varying sizes and colors are available. See all options by clicking through the following link:
Browse all Giant Balloons here.

Out of the many Giant Balloons available, I picked out the one you see here, due to the customer reviews. However, many others can be found through the links on this page.

The one are seeing here, is the Professional Quality 8′ Diameter Latex Weather Balloon. Burst 12’4″, 300 Grams Average Weight. Basically, if you blow it up full, it will be more than twice the height of the average man.
Read More About it or Buy it Here.

Pros: 

Great for parties. Solid positive customer reviews.

Cons: 

Depending on your use for these huge balloons, it may be a one time use purchase. In which case, be sure you really want it before buying.

If one giant balloon is not good enough for you, you could buy a 6 pack of them. This here is the white version of a 6 pack of latex 36 inch giant balloons. These are high quality and durable balloons that are completely helium compatible. They are made of natural rubber latex and they are biodegradable. As mentioned, these are the white ones, but you can get them in a wide range of other bright colors. Click the image to see them all and to read more details about these and other similar balloon products.

You can also find many larger sized mylar balloons for special occasions or for themed parties. Obviously you can see that this is a number four Happy Birthday balloon. These come in other numbers for other ages, this one is just an example. You can fill these with helium as well. These are 25 inches tall, and they are resealable when you fill them up which is very handy. See more details about these and other themed mylar giant balloons by clicking the image of the number 4 foil balloon you see here.