There are some original ideas, too. Most of them aim at simplicity and easy play, something modern commercial rules often forget. The "historical" aspect and simulationism usually do not lie within complex charts and percentage tables, but in the spirit of the game.
A relatively simple and fast-paced set of Napoleonic rules, based on Easy Tricorne.
Hex Conquest printable armies
A simple simulator for conquering barbarous hordes. Combat resolution is similar to Battles of the Riverland, and the rules include a separate chapter for setting up neutral zones and non-player factions.
Wargaming rules should have a format that is easy to read. They should not include over-explanations, purple prose and excessive / unnecessary imagery.
Regulations should be written and edited in such a way that does not allow for multiple interpretations. The intention of the designer should be clear from the way the rule is stated, without any additional explaining paragraphs, unless absolutely necessary. The language should be simple and to the point, but not overly repetitive.
General rules should always precede special ones in the text, and the reason for deriving a special rule should also be made clear from the onset.
A rule set thus need be no longer than 30 pages at its core, or four pages of quick reference sheets.
As no wargaming rule set would ever able to cover every single situation that arises during its use, it should be made clear why certain elements are included and others omitted.
In a wargame, nothing should be done that is contrary to common sense and the rules of the universe the game is taking place in; common sense should not always be obliged if this makes the game more entertaining.
The rules should always rely on the good will of the players' interpretation.