i.Hex is a tiny and efficient hexadecimal editing tool for Windows, Mac and Linux platforms. It enables users to modify the hexadecimal code of a file, supports copying data as hexadecimal, text or source code, as well as pasting data in hexadecimal or binary.

010 Editor is a fresh-new and extremely powerful text file editor & hexadecimal file editor developed by SweetScape Software from Canada. It is absolutely an egde tool especially when it comes to analyzing the binary files. But what impressed me most is its support for searching and replacing block-level strings with line breaks. This feature is rare in all similar programs.

Hex Editor Neo is a professional and powerful binary, hexadecimal file viewing, editing & creating utility for both 32-bit and 64-bit Windows. It came with abundant and convenient features, and was specially designed for software and hardware developers who often deal with ASCII, hex, decimal, float, double and binary data.

Modifying the data in memory can be not only used to decode/hack software, also used to hack all kinds of games (especially PC games and emulator based video games). Cheat Engine (CE for short) can make one game easier or more difficult, in other words, that's to be more suitable for you (but not necessarily to be more interesting)! Its principle is - the memory debugging/hacking.