Bear in mind that the pleasure you get out of your layout is directly proportional to the work you put into it. I've been working on my layout for just over two years now. I chose to build a fairly challenging layout, the Philadelphia-Reading layout I found in that 101 Track Plans book by Linn Westcott and just now am finally finishing the last of my yard area.
It's a layout that you cannot simply let trains run by themselves; you have to actually operate it throwing switches and stopping trains on sidings until others pass by, backing trains into and out of the yard area and deciding which locos I'm going to use to get a load of freight or passengers from one place to another.
Now if I'd settled for a quick snap together layout that could be put together on a table top in a couple of hours, sure, I'd have been up and running a whole lot sooner than it's taken me for what I have now. But by taking the time to do the bench work correctly, the roadbed, the track work, the wiring, the switches, and everything else, I have a pretty complex layout that is a joy to run. I can run a combination of routes and trains and not have to see the same thing twice for a long time. Watching the trains as they pass each other and crossover and under is to me what it's all about. The concentration required to run 2 or even 3 long trains at the same time can be pretty challenging too. Thank God for DCC!
In the end, you really do get out of it what you put into it. Good luck in choosing and let us know what you do.