Which scan tool is best for everything, but on a budget?

I am a DIY kind of mechanic and will only send my vehicle to the mechanic shop if it's something out of my scope of knowledge, or something that requires tools and equipment that I don't have access to. I just sent my car to a mech shop only to find out they can't get it going and to tell me exactly what I had narrowed it down to, and now less the money for diagnostic! Which tool out there is good for a person on a budget, but can basically scan and program any problem on a vehicle? I have a xtool scan tool currently, and it does quite a bit but doesn't have the ability to program or flash the PCM/ECM or the BCM which is what I will possibly need for the car I'm working on currently. I've been looking at different scan tools, thinking about getting a tech 2 but I want something that I can work on other vehicles with that won't require a standby laptop to go with it like the VXDIAG VCX Nano GDS2 to make it work for whatever I may need to do, unless that is the best option. Your advice is much appreciated!