Web designers often forget that there are two large internet viewing audiences when they create their web pages.
In the past the majority of web viewers used a viewing resolution of 800 x 600 for their browser window. However, today the majority of users now use higher resolutions like 1024 x 768 due to the fact more users are buying larger screen monitors. However, there are still lots of 800 x 600 viewers yet out there too.
Often a good web designer will center the web page so that both viewing audiences can see the web page without having to scroll. There are other methods to achieve this through the use of CSS and recognizing what browser each user is viewing the web page and providing the correct sized web page to them.
You can also change your own video display settings and try using a display of 1024 x 768 and while things might look smaller, you will be able to see the entire web page. In addition, you can invest in a wide screen monitor which will show you everything and it's very easy on the eyes too. I purchased a nice 19" Acer wide screen monitor for $150.00 and I love it.
Lastly, you can also try holding down your CTRL button while moving your mouse's scroll button and that will increase and decrease the font size of any web page. That might help you to better view different websites.