Hi @terryjohn !
When it comes to locks you have a lot of options. It really all depends on where you need to secure it and if maximum security is needed or if it’s just for a general precaution. In either case I think Kryptonite locks are great. Here are a few options that you might consider.
Another option would be to use a cable paired with a standard padlock or combination lock.
Hopefully this helps!
I agree with everything that @REI-AlyS said.
I personally have always gone with cable bike locks that are long enough to wrap around both tires (you can create a figure-8 through the spokes), which prevents 1) one tire (typically the front) from being removed and stolen and 2) one tire being left and the rest of the bike being stolen.
The lock I have used for the past 5 years is from the OnGuard Doberman Series and has gotten me through 4 years of college and traveling without any issues. OnGuard has a range of bike locks that vary in their price based on security level, length, thickness, etc. I know several people that use other bike locks from this company and love them. The Doberman Series specifically ranges in price from $16-$35.
I have also heard that the Kryptonite locks that @REI-AlyS mentioned are good, but do not have any personal experience with them.