My guess is that on account of their relatively high price, your average FTAer doesn't have a spectrum monitor. However, to answer your question, at work I primariy use a Tektronix 1705A spectrum monitor which is generally considered the gold standard for spectrum monitors in the tv broadcasting industry. At a list price of $7,000, it's well out of the price range for your average FTA hobbyist, but its resolution and refresh rate far surprass any other spectrum monitor I've ever used. The 1705A is purely a spectrum monitor and doesn't provide any satellite or transponder identification, so its necessary to become familiar with the spectrum footprints of various satellites if you're going to use it for identification, but nonetheless it's an excellent instrument.
There are many on the maket, take your time and get the one that you think will be best for you, reading up on it and asking others who have used them on the field is the best way to get the right one.
If you are looking for a "simple affordable" SA for dish installation, get an analog one such as SAtlook Mk3. It is a nice unit for dish installation but you won't be able to see the bandwidth and other cool things in the real SA.
BLSA is a nice tool to have for feed hunter but the scan rate is really slow, not really useful for dish installtion.
Keep an eye on ebay for used Avcom units such as PSA35/37...you might get one less than $500....
HP and Tektronik are probably out of hobbiest budget unless you are willing to spend tons of $ for them, and have a pretty good knowledge on how the SA works in order operate these units and ultilize all the functions.
Well I've done enough installs without the help of an analyzer and I'm ready to pick one up. I have plenty of experience with them, though they're more of the bench type.