I do not want to go into detail on individual systems here, but rather give some general remarks:
The fact that most RV systems have huge planets compared to the transiting ones is not rooted in the way I present it; the RV technique is not yet capable of measuring the masses of the smaller planets detected with transits. You can also see that in my post on detection methods.
Most exoplanets are closer to the star than the solar planets; exoplanets with orbital periods of years and decades, which would be far out in a system, are very tough to detect.
Finally, the smallest planets usually orbit stars smaller than the sun. This again is caused by the transit and RV method, which depend of the relative sizes or masses of host star and planet. Thus, the conclusion that less massive stars have less massive planets is tricky because for the more massive stars they are much harder to find.
In upcoming posts I will present diagrams of - and talk in detail about - several systems shown here individually. As you might already suspect, all of these systems are highly interesting.
(Link to a hi-res pdf version of this diagram.)
Addendum: In this diagram I only considered planets from transits or RVs. This is why HR 8799 (direct imaging) and PSR 1257 12 (timing) are not included. Unfortunately, for quite a number of shown systems planets are missing; this is due to the exoplanet.eu database not providing the semi-major axis (distance) of these planets.