What will be the best software to use in a design? (e.g. games, or something useful)
The best software to create and or to design, in my opinion, has to be categorized into separate functions. You mention "Games", in video game design the best software used today is called "Autodesk (formerly Alias) Maya." It is a 3D animation software and it used on many of the video games on the market today. "Maya" is also used on feature films like "Shrek" for its 3D animation. the background scenes and for special effects. Other uses of "Maya" are architectural design, automobile design. jewelry design and industrial design. Still others are virtual avatar design like the avatars of website Second Life. Autodesk Maya is not cheap and depending on which version you use the price could be very expensive.
Other animation software used in video games are Adobe Flash and ToonBoom Animation. Both are 2D animation software, in 2D we mean the classic look of old cartoons. Adobe Flash is a web based animation software, where as ToonBoom, while is web based, it also outputs to film, video and the web. ToonBoom has been used on commercial TV like the "Simpsons", both TV and the theatrical movie. Another TV and movie where ToonBoom is used is "SpongeBob." ToonBoom has different versions too for the individual user which are considerably less expensive.
Other software for designing is "Adobe Photoshop" and "Adobe Illustraor." These two don't use animation but deal with the pure 2D design of photo manipulation, photo-painting and illustration. Even though these softwares require education, talent and skill, all of these are virtual and truely magical in the artist's hands.