MarketWatch has Investor Tools, Stock Research Tools
eMasterTrade lists advanced tools for trading and investing 
InvestorGuide.com has sections that benefit everyone equally are those covering online brokers, stock information, and a comprehensive list of publicly traded companies (including home pages, research, and discussion.
SchaeffersResearch.com has a wide aray of tools, some of the best we've seen.
NASDAQ: Stock Research Tools - Stock Market Research - Free Investment Research
StockScores: There is a wealth of knowledge and easy to use tools available on the site completely for free. Serious traders should consider the more advanced tools and educational products available.
Kiplinger has  tools for stocks, funds, bonds, budgeting, college, credit, insurance, real estate, taxes, retirement, savings, retirement income  and more.
Morningstar: Investing Tools & Calculators
MarketEdge: Whether you are a first time investor, a seasoned pro, an "in and out" day trader or a long term investor, Market Edge will provide you with the tools you need for success in today's dynamic markets.
Yahoo! Stock research center has many varied and interesting tools as one would expect.
SmartMoney.com also has an interesting and unique set of tools for investors.
StockCharts.com: Our SharpCharts tool lets you create the web's best looking financial charts. Our Scan Engine shows you the market's best investing opportunities. Our Chart School is full of easy-to-read educational articles.
Forbes has a variety of interesting and different investment and planning tools
Choose to Save provides investment calculators in eighteen different categories
Looking for an investment tool?  One of these sites may have exactly what you need.
FundLibrary.com has a Tools Directory that will enhance your understanding of the markets by crunching numbers and charts.
Chicago Board Of Options Exchange offers a wide variety of trading tools to help you make more informed trading decisions.
optionsXpress has a stock and options related toolbox
Quote.com has a Trader's Toolbox
Briefing.com has wide and varied investing tools.
Market Riders online software that lets anyone invest using asset allocation
Personal Capital An effortless way to gather all your accounts into an organized dashboard.