Well, filter choices depends on a number of factors but it really comes down to personal choice and as long as the filter, be it HOB, external cannister or internal filter is suitable for the tank size and stocking / bioload waste.
I have used all three different types over the years and I have no real preference for any except that the internal takes up space inside the tank and can sometimes look somewhat bulky.
So that leaves the choices between the two types, cannister and HOB, both have pros and cons.
HOB has much easier access for those maintenance services of the impeller and general clean every now and again so thats a big plus in my book. You can actually use whatever media you choose as long as theres room for it, my own HOB originally had these silly cartridges and I still have them unopened in the packet! :d I just simply swapped those cartridges for sponge, a few ceramic noodles in a little bag at bottom and filter floss on top, works very well I have to say, keeps the tank flowing nicely and crystal clear water as I do change the filter floss every week.
I have another HOB by Fluval on my 25 gal long that actually has separate pull out trays for the sponge, ceramics and filter floss, this is a nice feature but not all HOB's have this.
Cannister does have a lot more space for much more media of your choice so that something you must consider, especially for larger tanks as well as if you having say plecos or BN as they are basically poop factories so you need something with lots of media to deal with that kind of bioload. Maintenance cleans are less often than HOB's but can be a bit of a task lifting out a heavy cannister full of water from the stand cabinet and opening the filter up without water going everywhere (double tap connector valves on the hoses are a must imho) I tend to use a sink basin and put the cannister in the basin to catch any water runnoff from the filter (a bucket works just as well but access to open the top of cannister can be limited this way).
Basically HOB is more maintenance cleans and limited to media quantity but access a doodle, while cannisters rquires less maintenance and holds more media but more troublesome to do the maintenance cleans.
Don't forget, cannisters, depending on the size you have can have much more flow so that could be useful in whatever stocking choices you have.
Personally I feel larger tank should have cannisters as a matter of choice but this is not always feasible so 2 HOB's would still be a good choice for large tanks.
It all depends but I think the choice of filter really should suit your tank size and stocking choices, that imho should be the deciding factor.