Gmail

Again, Google has redefined the way that an application should work. While most web-based mail services feel like traditional web sites, Gmail feels almost like a desktop application with its heavy use of client-side scripting to handle more activity in your browser.

So why do I like Gmail? Let me count the ways. First, Gmail is free and gives you a copious amount of storage space -- more than any other free web-based email service.

Second, they created a novel way to view conversations (or threads) -- by stacking just the subject lines in chronological order so you can see who responded and when. This approach makes it easy to keep up with a thread of multiple responses.

Third, Gmail uses the concept of tags, much like Flickr and del.icio.us, to categorize mail messages. For example, you could assign a tag of "Orders" to all of your online orders to easily find all messages relating to orders.

Fourth, Gmail employs filters to allow you to automatically forward, categorize, archive, star, or delete your incoming mail.

Fifth, Gmail's spam filtering is pretty accurate. I have had very little of my mail wrongfully marked as spam.

Sixth, Gmail uses shortcut keys to allow you to quickly handle your mail. A lot of people don't know about or use this feature, but I can quickly reply (r), forward (f), archive (y), or go back to my Inbox (u) with just a keystroke instead of hunting for the correct button or link to click on.

And last but not least, Gmail uses Google's famed search engine to allow you to quickly find the message you need. With all these things going for it, it's no wonder I love Gmail so much.