TL;DR: Here's the axe, my liege.
10/10 would ♥♥♥♥ off the scribe again
It's $20 for a massive collection of all the greatest stronghold games (aka anything pre-stronghold 3). What you're getting is...
The original Stronghold from 2001 - a game that has aged tremendously well and looks good to this day. You build your castle and defend it from various warlords that would seek to destroy it through RTS mechanics and controlling large armies of medieval soldiers while keeping your castle happy, or simply build peacefully however you wish. Comes with a map and scenario editor and a HUGE community with downloadable maps and scenarios too. The HD remake included here also has some of these community maps and missions built in.
Stronghold Crusader (2002) - This was where stuff got interesting as this implemented AI for building castles and such, meaning now you could play against AI opponents building their own castle across the map and be rushed to simply have a better one than them before armies clash. The original stronghold had multiplayer, but the faster paced style of this one plus literally double the amount of units you can train thanks to mercenary outposts makes it considerably more fun to play with friends.
Stronghold 2 (2005) - This was the first 3D stronghold game to be released, and at the time of its' launch had massive bugs, crashes, and performance issues, much like a certain Stronghold 3. Difference was, they FIXED stronghold 2. The game now has a larger scale to it, with campaign missions that can span large amounts of time on a single map thanks to numerous objectives and AI castles to deal with. Bringing back AI castles and mercenaries from Crusader, this also adds in a new type of granary - the Lord's Kitchen - with 4 new types of food for your lord and various guests that magically appear during times of battle without the enemy noticing. It also goes back to Stronghold 1' style in a way, doing away with deserts and bringing back the worthless wooden walls that are brought down by peasants, as well as a new resource in the form of honor which encourages the use of the new buildings, as honor is now used to train most troops and mercenaries. It also adds in the "estate" system, which are little villages around the map that can be purchased/captured and will send you resources via horse cart, which can also be used to send your allies resources. Multiplayer is especially fun, although the inability to add AI castles during multiplayer matches (singleplayer only) is a bit upsetting.
Stronghold Legends (2006) - Based heavily off of Stronghold 2, this game features 3 different factions you can play as which now varies your gameplay massively. Taking place in mythical times, you can play as the good, the ice, or the evil, with it changing the look and play style of your castle along with it. The good side plays very much like normal stronghold, and is therefore very easy to pick up for veterans, but with the addition of King Arthur's knights of the round table as trainable, highly powerful knight units. The ice style adds in new flying units and ice-based giants and such, while also having its' own graphical style, new music, and some different structures you can place in addition to normal ones. The evil side has all sorts of weird creepy-crawly things that can easily overrun your castle, climbing right up and over walls and demolishing things easily, once again with its own visual style, music, and different structures. This also brought back adding AI to multiplayer games, allowing PVE gameplay with friends. Problem is, this is also the most glitchy game in the bundle, with AI that openly cheats by having access to things they should not be able to build yet, and also some strange changed things such as markets being absolutely useless, strange prices for resources, and other various things...oddly enough, it's these changes that people didn't much like that were kept in stronghold 3 and crusader 2. Still worth a play though.
Overall...for $20, you get 4 fantastic games that are going to give you a fantastic time playing. Make sure to get a program called "Gameranger" however, as all 4 of these games ran on gamespy for multiplayer which is now down - gameranger lets you play with friends or publically by using its' own servers rather than gamespy. Have fun!