Add me as a vote for excel spreadsheet. Several times I thought about going with LogBook Pro or one of the competitors but I always balked at the price and the fact that you never know how long those companies may last. I know LogBook Pro has been around a long time now, but it's still impossible to know if they'll still be there 30 years from now.
There are a couple of templates floating around out there you can use, but I ultimately just made my own and it works great.
I also still paper log as well. Frankly I enjoy the personal touch of logging everything in writing and I hope it is something my kids or grandkids will find interesting in the future. I know I cherish my grandfathers hand written log books. Plus, I figure you can never have too many back ups if you are a professional pilot. I not only have my paper logs, I have my electronic log book saved to my laptop, to a cloud, and to an external hard drive.
Bottom line, save your money and make your own electronic log and also keep doing paper.