Where is my dream OS.

If ur tired using Winows, Linux , Mac, *BSD there are few other u can try.
There are operating systems u can try, might be one of them suit ur needs.

SkyOS
Started in 1996 and still in beta, SkyOS is primarily developed by just one person, Robert Szeleney. This proprietary OS has a lot of good things going for it, such as symmetric multiprocessing support, an integrated media subsystem, and a journaled 64-bit file system that lets you recover a partition in the event of a crash. Application support is limited, but SkyOS offers Mozilla Firefox and Thunderbird, AbiWord, Gaim, Nvu, and Pixel, among others. Installing application software is simple via the SkyOS Software Store; all it takes is a few clicks of the mouse.

SkyOS also offers real-time file content query searches with multiple keyword support, similar to Beagle in Linux or Spotlight in Mac OS X. Files and programs are indexed for easy access. Also included is support for system-wide mouse gestures, and a media player application that uses ffmpeg for multiple codec support, including Windows Media Video and MP3.

Haiku
After Be Inc.'s assets were bought Palm in 2001, a group of BeOS fans created the OpenBeOS project to write an open source operating system (under the MIT license) that would be backward-compatible with BeOS 5. The project, now known as Haiku, has made some progress since it started. A lot of programs can run on the system, including Mozilla Firefox and SeaMonkey, as well as some games and other programs.

While Haiku offers short boot times and application load times, networking adapter support is very limited. Also, installing Haiku requires a BeOS or Zeta system installed, and an extra BeOS partition to move the Haiku files onto.

Syllable
Syllable, created in 2002 as a fork of the now-defunct AtheOS, is a GPL-licensed open source desktop OS. It has modest hardware requirements and boots quickly. Although the choice of application software is limited, there are Web browsers, email programs, games, and a media player. To install the majority of the software, you just move a binary file out of an archive. Syllable also includes a 64-bit file system, the AtheOS File System.

Syllable's hardware support can be lacking, and installing Syllable can be an adventure for some, as the installer is text-based and can be confusing. However, out of all the operating systems in this list, this is the most ready to be used as a secondary OS.

ReactOS
The ReactOS® project is dedicated to making Free Software available to everyone by providing a ground-up implementation of a Microsoft Windows® XP compatible operating system. ReactOS aims to achieve complete binary compatibility with both applications and device drivers meant for NT and XP operating systems, by using a similar architecture and providing a complete and equivalent public interface.

ReactOS components are growing more and more compatibile with equivalent, closed source alternatives, but ReactOS doesn't simply stop at an arbitrary line in the sand. ReactOS has and will continue to incorporate new versions of the Win32 API and so will track and sometimes even define the state of the art in operating system technology. Rather than using current technology as a limit on our activities, we are constantly incorporating features from newer versions as well.

If any one of these does not satisfy ur needs , then u always have one more option "write your own os".