I have used the majority of them; h5g,logo infusion, apparel efx, boom, Gemini...
By far my best experience has been Apparel EFX. The prices are very fair, but more importantly, they are very quick to respond and send proofs fast. For me, I typically order online and will have a proof within a few hours. Most impressive was the proof was very well designed and required little to no modification. The people there seem very creative.
Logo Infusion is definitely one of the best priced, but they charge $10 for a digital proof which really annoys me. Without the proof, you will get very basic logos, etc. and are stuck with what they send. Also was a few days wait just to get the proof, then had lots of modifications. Glad I spent the extra $10 for the proof, but otherwise, wasn't very impressed. Jersey was nice and material is nice. Not bad if just looking for something quick and are willing to go with one of their stock designs.
H5G makes great jerseys, used them for 25+ jerseys for nationals and some personal jerseys, but takes a fair amount of time to get them, and if you want customization, email chains tend to take a while. Not to mention, they are definitely more pricey.
The others aren't really worth mentioning. Check out Apparel EFX in my opinion. They also do special designs on facebook every so often for $59 shipped with logo and name. Its a killer deal.