1. Helps you separate the presentation (XHTML) with the client side logic – following the “Unobtrusive JavaScript” principle.
2. Let’s you forget about having to code like “if (IE) write_yet_another_hack()”. It abstracts 90% of code that needs to be browser-specific and smart enough to catch the different browser divergences (especially the “blue e” on your desktop).
3. Makes your code fly with its fluent design – chaining methods like $(“.nav”).show().addClass(“red”) – can the code be more beautiful ?
4. Writing your own plugins is extremely easy. This is why you have tons of extensions to choose from if what jQuery offers to you out of the box is still not enough.
5. Rounding corners, adding animation effects, working with ajax and other popular client code tasks haven’t been that easy before.

I’m currently finishing reading the “jQuery in Action” book and I can tell that I definitely fell in love with this framework and I am more than sure that I will never go back and write plain old JavaScript when I only have a choice.

There was actually one drawback – the lack of intellisense. If it is a drawback indeed, because simple JavaScript intellisense support in VS hasn’t really blown me away either. However, since recently intellisense for jQuery is available to download as a standalone .js file, that you need to reference inside your script files.

Intellisense in jQuery

Sweet! isn’t it?  Check for more information about intellisense support on Visual Web Developer Team’s blog.