So about 6 months ago I picked up my starter bike. It was a 1995 BMW r1100rs. I did a lot of research prior research on what the best starter bike was and it's not something you ever see mentioned.
I've found this to be an amazing starter bike and something you can really grow into.
Here's some of the reasons I think the R1100 rsl is a great starter.
1) Cost: these are obviously not the most popular bikes out there as they don't really fit into any specific category and therefore a great condition one you can pick up for about 2500. Not a huge investment for a beginner just trying to get started
2) Reliability: it's no secret that the oil head is a pretty sturdy and reliable engine. As a beginner, obviously the last thing you need is a bunch on mechanical problems while you trying to learn.
3) Power/Range: As a touring-sport, you get the best of both worlds. As a new rider you want to get a taste for different aspects of riding to see what suits you. You'd be surprised what sport bikes this thing can keep up with, but also allows you to rack up some serious miles on a long roadtrip and stay comfortable. At the same time it's not a hugely overpowered bike which most new riders wouldn't be able to handle.
Anyway that's just a few reasons why I think the R1100rs is a good starter bike. Don't get me wrong, they have a few drawbacks. They ain't the prettiest bikes for sure and since it's doesn't really fit into any category you always kinda look put of place on group rides. Other than that I got no real complaints!