Guys - be a little careful here. In a previous life I was a radio engineer. You may gain the extra 'range' by placing the aerial at the top of the mast but given the polar diagrams of each antenna, the lack or provision of a ground plane and the incredible losses in 'normal' 75 ohm feeder it is a little more complicated. An omnidirectional aerial (such as the glomex or 'UFO' as described) can be very versatile (I have one on my boat and it works really well). These also tend to have pre-amps in the aerial built in with the power supply and additional amplifier which can be sited somewhere in the dry! Yagis (or 'directional') aerials have much greater gain in one direction so better for avoiding 'ghosting' which is a reflection of various signals but this is more noticable on an analogue signal. Digital tends to ignore weaker signals and given the nature of its design its either 'on' or 'off i.e. if the signal is reasonable then the picture will be perfect.
I'd go for a decent omnidirectional antenna, good quality feeder and decent connectors anytime (also you don't have to know where the transmitter is located which is a problem the more directional the antenna). You may have a few more areas where the signal is not good but it more than makes up for the hassle and manual intervention required for a yagi although more affected by the proximity effect. Horses for courses, different requirements for the various situations really. I've probably just confused the thread now but happy to help anyone who would like more info.
Satelite gives its own problems and depends on how much you want to spend, anywhere from the self tracking to the manual alignment (such as those supplied in a small suitcase type container designed for portable use). Again basic rules, good feeder, good connectors (and made properly although the popular 'f' connector is reasonably idiot proof and is good electrically but diabolically on the mechanical front!
Dave