The first one that comes to mind for me is The Ur-Quan Masters.
That really rekindled my love for Star Control II all those years ago.
The Ur-Quan masters is not so much a remake as a port, but it is
a fantastic game. The recent HD version of it is also amazing! They really kept to the style of the original graphics, and simply recreated them in a much higher resolution. I highly recommend it.
When talking about good remakes, I have to mention The Settlers II: 10th Anniversary Edition. That's the proper way to do a remake. Update the technology, change the things in the interface that didn't work, and keep everything else, including the graphical design, despite the change from 2D to 3D. I was so
impressed when I tried it.
I finally bought Half-Life 2 so I can install the Black Mesa mod and I am amazed that a mod group made something of this magnitude so I like to ask what is your favorite video game remakes.
I hope you bought Half-Life 2 to play HL 2 and not Black Mesa, which only needs the Source engine, which it will download itself once you install it.
Yeah, you don't need any commercial game to play Black Mesa. It just needs the Source SDK (2007 version I think), which you can get from Steam for free.
That said, HL2 is a fun game, so your money is definitely not wasted.