twenty-one jquery & CSS effects I like. Enjoy.

1. Premailer — preflight for HTML e-mail
2. jQuery Inline Confirm
3. 8 Ajax Data Controls and Effects to Work with Tables
4. jQuery plugin: ‘autoResize’
5. DataTables: highly flexible data table component
6. jQuery-gestures
7. Animated Ajax Record Deletion Using jQuery Example
8. Moving Boxes
9. 10 Smart Javascript Techniques to Improve Your UI
10. IE Fix: Bicubic Scaling for Images
11. Text Effects Plugin
12. KeyTable: Instant keyboard navigation in a table
13. sevenup
14. Spell Check - Instant Website Spell Checker
15. Overlay your HTML with eyecandy with jquery overlay
16. Styleneat - CSS Organizer
17. jQuery Tabbed Interface / Tabbed Structure Menu Tutorial
18. Simple Photo Gallery
19. MenuMatic
20. A fancy Apple.com-style search suggestion
21. Sliding Boxes and Captions with jQuery

View all Tech Toolbox posts.

Following Tech ToolBox: more jquery & CSS effects I like.
.
thanks @elijahmanor & ajaxrain for most of the tips.

• Accessible News Slider
• Fade Out Bottom
• Fix My HTML
• Web Development Project Estimator
• JQuery Drop-Down Combo Box
• How to Make a Smooth Animated Menu with jQuery (tutorial)
• 
  Create an apple style menu and improve it via jQuery
• jQuery Editable Plugin
• jQuery FadeI/fade Out Effect
• Menu Fader
• Fixed drawer slide out demo (using accordion plugin)
• Unobtrusive JavaScript date-picker widgit
• create astonishing ical-like calendars with jquery
• CompareNetworks jQuery’d Bread Crumb
• Moving Boxes
• Coda Popup Bubbles

I tuck all cool effects I find under a TOOLS bookmark folder… Below is my updated collection. It’s heavily slanted towards jquery effects, but you can find CSS tricks & other graphic design tools.

• Word HTML cleaner - A tool to strip Microsoft’s proprietary tags and other superfluous noise from Word-generated HTML documents, leaving all the basic goodness intact.
• Body Border - cool CSS trick
• jQuery ToolTip
• ecommr - a collection of e-commerce interface and design elements
• Spoonflower - custom fabrics
• Superfish - an enhanced menu jQuery plugin that takes an existing pure CSS drop-down menu and adds much-sought-after enhancements
• Favikon - creating favicons has never been easier
• SocialHistory.js - enables you to detect which social bookmarking sites your visitors use
• jQuery magicpreview plug-in - automatically updates selected elements on a page based on form fields. Perfect for previewing forms.
• jQuery pageSlide - sliding (or “throwing”) content aside to reveal a secondary content pane
• Color Fading Menu with jQuery - fading is the new rollover
• Animate a hover with jQuery - Animate an image while hovering it and show the visitors information while doing that
• Ctunnel is here to protect your anonymity online! Browse the web through our server to get past pesky url or ip based filters!
• VectorMagic - Convert bitmap images to vector images with a few simple clicks
• Blueprint Grid CSS Generator - generate more flexible versions of Blueprint’s grid.css and compressed.css and grid.png files
• HTML/XHTML Character Entities
• Convert TrueType Font to Sifr Flash File - Upload your font and they’ll send the sifr file to you
• .htaccess Password Generator - generate all the necessary codes needed to password protect a directory or selects files within it on your site via .htaccess
• Select Multiple Form Fields - Finding a better solution for multiple selection
• jQuery iPod-style Drilldown Menu - an iPod-style drilldown menu to help users traverse hierarchical data quickly and with control
• 
  Load Content While Scrolling With jQuery
• Galleriffic - A jQuery plugin for rendering fast-performing photo galleries
• CrossSlide - a jQuery plugin that implements in Javascript some common slide-show animations, traditionally only available to the web developer via Adobe Flash™ or other proprietary plugins
• Using jQuery for Background Image Animations
• Sliding JavaScript Dropdown Menu - easily add smooth transitioning dropdowns to your website
• Versionista - monitors any Website and alerts you when it changes, visually showing you the exact words and senteces that have been added or removed
• A brand new PNG fix for IE6
• prettyCheckboxes - a solution for people who wants to have a consistent look for checkboxes across browser or those who simply want them to look better
• Packaging Templates
• PatternTap - Interface collection for design inspiration
• jParallax - turns a selected element into a ‘window’ that moves in response to the mouse
• NEW dynamic basic CSS TEMPLATES
• ie7-js - a JavaScript library to make Microsoft Internet Explorer behave like a standards-compliant browser
• 4 Uber Cool Css Techniques For Links
• text2mindmap - convert your text to mindmaps
• bgPatterns - make or browse patterns on the web
• BigTarget.js - Increase the size of click targets and get more call-to-action conversions
• Multicolr Search Lab - Using visual similarity technology you can navigate flickr interesting collection by colour
• title - description
• droppy - Nested drop down menus
• Jquery DynaCloud - a dynamic JavaScript tag/keyword cloud with jQuery
• Lorem2 - An all-around better Lorem experience