Ports are a very common thing in gaming, and more often than not they aren't very interesting to think about. A game from one console shows up to another. But it isn't often where games from one console show up on a platform people would have never even thought was possible.

Xenoblade Chronicles(3DS)

Xenoblade Chronicles for the 3DS is highly regarded as one of the Wii's best titles, and one of it's largest games at that. So it was a surprised when they announced they'd be porting the game on a dinky 3DS cart for the New 3DS(specifically). However the dev team pulled it off, and managed to port the entire game onto the console, only slightly compromising the original game's graphics

Donkey Kong Country Returns 3D(3DS)

Another Wii to 3DS title like Xenoblade, and while smaller than Xenoblade, it's more impressive in the sense that not only was it made with the original 3DS in mind, but also manages to look as good as the original game being the definitive way to play the game using traditional controls rather than the tacked-on motion controls the Wii version used

Arcade Ports on Sega Consoles

When people always told you to buy console ports of popular arcade games, there's a reason why people would usually recommend the version on Sega consoles as opposed to the SNES or PS1 versions, regardless of the company. The Sega version would often retain almost everything from the original games while the SNES or PS1 versions would often lack features(ex. SNES Final Fight being released in two versions, one with Cody and one with Guy, both omitting the Industrial Zone; PS1 ports of Capcom Vs omitting the team-up style; both systems would often perform much worse.) Only company that didn't suffer from this(from what I recall) was Konami as their NES/SNES ports were normally faithful to the original, aside from maybe some weaker visuals)

Persona 3 Portable(PSP)

As the name implies, P3P is a portable version Persona 3 for the PSP. The Persona series experiences a boom in popularity, and so Atlus decided to rerelease the game a third time on the PSP(game was rereleased once before as FES on the PS2). What sets this apart is that despite some cut features(anime cutscenes and the overworld being replaced with menus and a cursor) they still managed to add a lot to the game. P3P gave players the option to play as either male or female, and this would alter a lot about the game despite the main story being the same. For example, interactions with other characters would often be much different from the male protagonist and shaking up Social Links, Igor's assistant could also be either Male(the new character Theodore) or Female(Elizabeth from the original game) and the game would also feature different tracks when playing as FP. Game also revamped the battle system, allowing you to control all of the characters(a common complaint from the original game was not allowing you to control allies) and included two new difficulties. Really the only thing that brings it down is that it's not the FES version.

Also I wish they'd give the Female Protagonist more love as I ended up liking her more than the male protag

Resident Evil 2(N64)

Easily the most impressive feat on the list, as this game should have been impossible to happen. Yet the dev team did it, they managed to fit 2 disc worth of content(700-800 MB, or 350-400 MB each) into a 64 MB cartridge and gave the game features exclusive to the N64 version, such as more alternate costumes, an item randomizer, extra documents expanding the game's lore, and etc. Many even go as far as to say the N64 version was the best version of the game, and is often regarded as one of the most notable programming feats in gaming