I love Plant Tycoon! Let this be a recommendation that you acquire it.

I made very sure to NOT look at any of the online charts so that everything would be a surprise, and I felt like a genetics researcher while playing. If you cross THIS kind of foliage with THAT kind of foliage, what will you get? Wow, it looks like THAT? Cool! So what will breeding one of the old plants with the new one produce? I had endless pages of notes, keeping track of what I'd crossed with what and what the results had been.

Now that I've played it once, I just make some pretty flowers, but the first time around, it was really fascinating. Of course, I love science, so "I feel like a genetics researcher" might not make everyone feel great.