This is the 2nd-best Battlefield of all times, in my opinion, with the best being Battlefield 2. So many unique aspects compared to both earlier and later releases.
I can't remember how many times I've played through its campaign mode, on every difficulty. This is the only Battlefield game with an "sandbox" campaign, where the player is given quite a lot of leeway in how they approach the objectives, relative to the franchise. It's such a waste that no other title in the series offers this approach, considering combined-amrs "sandbox" multiplayer was the root of the series.
Combine the above with the humorous story, small-yet-memorable-and-also-humorous cast of characters really make this the best Battlefield campaign, in my opinion. Even the introduction videos of the characters (or character blogs, as DICE called them) are funny, and further make them memorable. The best thing being all of them made it through the campaign alive, and in normal gameplay, they can't be killed by any means, whether by the player or the enemy.
Final piece of the puzzle is the introduction of (partially-) destructible environment to the franchise, being the first game running on DICE's Frostbite engine. This makes heavy weapons like RPGs/anti-vehicular weapons, as well as artillery and explosives in general, truly deadly, unlike other shooter games, since hiding behind a wall/concrete barrier no longer offers protection against such weapons. The developers also took advantage of this and sometimes built the game around this feature.
The olden games truly are different. This game running well-optimized on modern systems at 1920*1080 is another piece of the puzzle completed. One more game that's effectively lost media now, if nothing changes, since it's only available on either XBox 360 or PlayStation 3. Can only hope the GOG team can deliver the magic and free up the game for us to enjoy.