Markets Data Center - Wall Street Journal has it all, on one page 

Market Summary - intraday industry indexes including international markets

Market Watch - with chart of today's action and list of most active stocks

Market Charts - Daily candlestick 2-month charts of major indices with real-time action

Market Breadth Charts - Daily 2-month plot of Advance-Decline and New High-Low indices 

Index & ETF Data - composite/breadth data with trends identified and 52-wk high/low flagged 

Great Charts

FreeStockCharts - REAL-TIME intra-day charts of everything 

S&P 500 Sharp Chart - with Bollinger Bands, ADX, and other indices updated by StockCharts.com in real time

Most Active Stocks Gallery View - daily & weekly charts with continuous update from StockCharts.com

Sector Performance Chart - line chart of nine sectors over any time period, and economic/market cycle chart

S&P Sector Carpet - performance of 500 stocks grouped by sector

Intermarket Performance Chart - relationship between stocks, bonds, commodities and the dollar 

U.S. Treasury Yield Curve - can be created for any point in time, and with links to yield charts

Technical Analysis

Chart School - Generally a great place to learn Technical Analysis, including definitions of indicators 

ETF Investment Outlook - Features breadth and volume charts with rankings for over 100 ETFs 

Don's Funds - CHEESE CHARTS for industry sectors and ETFs, fund ranking, and the Tango5 Trading System

Stock Market Trends - different indication of trend updated daily by StockTiming.com  

Market Timing - Roy Ashworth's analysis of the market (click on Market Timing)

Chart Patterns Analyzed - Current support/resistance levels and patterns analyzed

Sector Charts & Ranking - charts in all time frames with signals updated weekly (investigate site to find much value) 

RiskGrades - Grades the risk of the market with maps for S&P 500 and Nasdaq 100, and your portfolio

Fundamental Analysis

Current Economic Data - Includes date of release, consensus estimate, actual value, and long-term chart. 

Investing in Bonds - Everything you need to know with current outlook. 

S&P NetAdvantage - JM Library (need card no.) gives company, industry, mutual fund data & ranking

Federal Reserve of St. Louis - Data & charts on the economy updated Thursdays

Articles of Interest - SafeHaven.com

Closed-End Funds and ETFs - Ranking and content, and plots of CEF premium/discounts

Pundits

John Mauldin - Thoughts from the Frontline (subscribe to excellent free newsletter) 

Bill Gross - A bond market analyst's monthly essay on the investment outlook

Jim Cramer - Recap of his "Mad Money" show, and news from TheStreet.com

Andrew Tobias - "Money and other subjects"

John Hussman - Weekly comments on the market

Arthur Hill - Goals, Style and Strategy for Investors

General Investment Websites

Kiplinger.com - Business forcasts, personal financial advice (including a forum), and many financial calculators 

Yahoo ETF Center - Exchange Traded Fund education and news

Yahoo Finance - News and views

MarketWatch from Dow Jones - News and views

IRA Planning - Required distributions defined and other IRA topics