Telling the Difference.
 

I've recently started to expose myself to Goth music. Thus far, I really enjoy the older style set by Bauhaus and Sisters of Mercy, but since I listen to Pandora radio while at work, it sometimes picks music that I'm not sure whether or not it could be classified as 'Goth'...or, if it -is- Goth, what -kind- of Goth it is.

Some of these bands are:

Tiamat
Depeche Mode
The Mission UK [I'm pretty sure this is Goth, but still not certain]
Red Lorry Yellow Lorry
New Order
The Cult
The Jesus and Mary Chain
Paradise Lost
et. al.

I know this may sound a bit silly, but is there a list of Goth bands compared to non-Goth bands or something that I could compare some of this music to, especially where the 1980's stuff is concerned?

Ackk ;P I'm not one to separate music by genre, but I can tell you that all of the bands you mentioned have goth sensibilities in some way or other.

And then you've the countless subgenres of goth: Darkwave, Gothic Metal, Electrogoth, Aggrotech, Gothic Folk etc. etc. etc.

Pretty much any genre can have "goth" added to it.

Tiamat - Doom Metal
Depeche Mode - Synth Pop/New Wave
The Mission UK - Goth Rock
Red Lorry Yellow Lorry - Goth Rock (earlier)
New Order - New Wave/Alternative Rock
The Cult - Gothic Rock (before reforming)
The Jesus and Mary Chain - Alternative Rock
Paradise Lost - Gothic Metal

These are just general categories that these bands get dumped into for the whole of their material. A certain song may have individual elements that make it a really good Goth Rock song done by a Post-Punk band. Wouldn't worry too greatly as to what category these bands fit into, unless you're trying to answer genre-specific questions from people like; "What's your favorite Goth Rock band?"

In which case, they have several websites out there that break down these bands into individual genres. Wikipedia is probably your best bet for a universal collection of widely accepted (by fans and industry critics) categorizations for a countless number of music groups.

Tiamat and Paradise Lost I'm not familiar with.

Depeche Mode and New Order are both synthpop, though both have some dark themes. Noteworthy is the fact that New Order comprises the remaining members of Joy Division after Ian Curtis' suicide.

The Mission UK and Red Lorry Yellow Lorry are solidly goth.

The Cult is just hard rock, but frontman Ian Astbury's earlier bands Southern Death Cult and Death Cult were goth rock. It's amusing how his band's name shortened as his music became more and more commercial.

The Jesus and Mary Chain is they're own flavor of post-punk, but they're one of those bands who are commonly liked by goths.

Here's a list of goth rock and deathrock (an extremely close genre, often simply lumped in with goth rock) bands off the top of my head:

Joy Division (proto-goth)
Bauhaus
The Cure (in their early years, then off and on)
Siouxsie and the Banshees
Fields of the Nephilim
The Sisters of Mercy
The Mission UK
Red Lorry Yellow Lorry
The Bolshoi
The March Violets
Christian Death
Shadow Project
45 Grave
Kommunity FK
Alien Sex Fiend
Danielle Dax
Sex Gang Children
Specimen
Diamanda Galas
Rosetta Stone
Cinema Strange
Tones On Tail

Some bands/artists not goth themselves, but commonly liked by goths:

Echo and the Bunnymen
Nick Cave and the Bad Seeds
Tom Waits
The Dresden Dolls
Ministry
Lydia Lunch
The Jesus and Mary Chain
Cocteau Twins