Brown Driver Briggs Gesenius Hebrew Aramaic English Lexicon
Easy to use presentation but be careful to use the Lexicon and not be distracted into lesser quality aids embedded on the same page. Chose a verse, click on the number associated with the phrase you want to explore, then search the resulting page for the specific verse in the Brown-Driver-Briggs section.
Robertson's Word Pictures In The New Testament
Lot's of advertising but the best online layout I've seen