There are several bitcoin chart websites on the internet. Here are my favorites. I tend to stick with Bitcoinity since the number is nice and big and Yoda will appear on screen if BTC reaches an all time high :)
BITCOINCHARTS - http://bitcoincharts.com/charts/mtgoxUSD
As a part time investor on the side, Ive found this is the closest charts you will get to those seen on ETRADE or AmeriTrade stock websites. Absolutely TONS of parameters and variables in comparison with the other chart websites listed below. Symbol, time period, chart type!, and even indicators like the MACD, Bollinger Bands and Stochastics. Tons of data at your finger tips.
BITCOINWISDOM - http://bitcoinwisdom.com/
Nice and simple customizable chart. Not over the top at all. Just clean and simple. Easy to change parameters and chart settings. Quickly change time frames and seetickers for most all of the markets. Mt.Gox, Bitstamp, BTC-e, BTCChina, LTC/USD and plenty more.
BITCOINITY - http://bitcoinity.org/markets/bitstamp/USD
Bitcoinity has a nice big number and a nice big basic customizable chart.
COINMARKETCAP - http://coinmarketcap.com/
CoinMarketCap show mini charts for all the cryptocurrencies listed in order by market cap. Its handy.
BLOCKCHAIN - https://blockchain.info/charts
Various bitcoin charts and currency statistics on BlockChain if you want to look more in depth.