OK, I'll be nice.
1. scalar variables & nonscalar variable arrays - basically, using memory to hold data for later application.
PRO: Very fast to find/use. Flexible. Easy to understand (since you designed the memory layout yourself).
CON: Frequently in Access, you want your information stored in a table. There is a hard barrier between variables and tables. It is extraordinarily tedious or outright difficult to bridge that gap. Can be hard on system resources when requirements get big. You have LOTS more disk than you have RAM, but to use variables, you need RAM.
VERY BIG CON: Memory resident variables can vanish on you if you have an unhandled exception in the module that defined the variables.
2. dictionary objects - not even sure how you could control this except by defining some metadata within a project. The object browser could see the metadata.
PRO: not familiar enough with this to address it much.
CON: very difficult to define in a useful way.
3. collections - Office Automation uses collections a lot. A BIG lot. But they are somewhat combersome. Collections of objects that you define can be a useful thing. If the objects are intrinsic to Office, not always as useful as a user-defined thing.
PRO: When a collection is exposed properly, more than one type of program can get to it.
CON: Definitional rules of what goes into a collection can often get in the way. Certain properties are forced by the nature of collections.
4. properties - Objects have properties that can be quite arbitrary in nature. Formats can be anything.
PRO: Where a user-defined object has a set of useful properties, it becomes possible to use the objects to organize the entities and their properties. If the problem is modeling, object properties are the way to go.
CON: Takes a non-trivial amount of setup to get things working right. Also subject to vanishing when the objects are an a context that can vanish due to mis-handled exceptions.
5. controls on forms - This can be just about anything you want it to be, but it is limited in some ways.
PRO: Lots of variability in what is defined. Easy to define a method for converting to long-term storage. Very visual in nature.
CON: Limited by screen space. Content must be saved before the display closes down. I.e. ephemeral.
6. tags - an "Other" property of controls, text oriented.
PRO: Ubiquitous. Capable of retaining useful information of various sorts. Flexible. Easy to get with VBA code.
CON: Limited in number, one per control or form object. Without VBA, very hard to get to.
7. recordsets & tables - THE #1 place to store things long term. Requires a table definition (and one or more address definitions.)
PRO: Capacity is extremely high. Flexibility is pretty good, too.
CON: Not quite as easy to random-access as memory. Easy to screw up the design.
8. custom objects - see discussion of properties.
9. registry - provides lots of space and subroutines exist to visit the registry from Access.
PRO: Elements are uniquely findable.
CON: Interface puts the "U" in Ugly. Danger is always part of getting into the registry, particularly given the bad behavior that can be triggered by hitting the wrong registry key
10. external file - the ultimate in flexibility and capacity.
PRO: You don't even have the Access 2 Gb limit on size.
CON: For really big files, it will take a long time to process. More likely to be linear than random in terms of file addressing.
The above is not meant to be exhaustive or definitive. Just opinions and random thoughts.