I have a JLab Crasher, a Pyle Marine, and a Lynx speaker. Each have some good features that may lead you to one over the other.
Lynx -- best price point of any of them. It is functional as a Bluetooth headset but not the best speakerphone out there. This will not get booming bass or the biggest sound but is a really nice sub-$20 speaker. I use mine in the bathroom when I clean, shower, etc. This probably isn't a bad option for a guestroom. The AUX jack is very useful.
JLab Crasher -- this one is probably the best all around. The Bluetooth speakerphone works well and I sometimes use this for conference calls. Sound quality is good, battery life is amazing, and as an added feature, you can charge other devices using the USB port. I have given these as gifts. This also has an AUX jack. I use this as the main PC speakers for my little Asus netbook.
Pyle Marine -- this is a solid, heavy, good sounding speaker. This speaker provides pretty good bass for its size and overall sound quality is great. The battery life is respectable and the loop on the end makes it good for hanging. I use mine primarily on the patio or when working in the yard. I will sometimes hang it from a shepard's hook or a hook for hanging plants when I'm outside. I have not submerged it (not recommended) but it seems to hold up to splashes pretty well. I liked mine so much I gifted one to an outdoorsy friend of mine that boats, camps, hunts, and has creekside parties on the property. This does not have an AUX jack. I purchased a separate Bluetooth transmitter to use with non-Bluetooth devices like the Zune or my older Sansa players.
Best price -- Lynx
Best features -- JLab
Best sound -- Pyle