Justin.tv - free, no need to register... will have to browse around to find what you need but usually only 2 pgs deep - might have to deal with 1 15sec intro commercial
LiveScoreHunter.com - also free, no registration required, better organized by category, great for a number of sports - might have to deal with 1-2 15sec intro commercials but nothing invasive like 10 pop-ups etc.