[22pistol]

Like to keep it under $300 if possible.

-Pump or Semi-auto?

What else should I want on a home defense weapon?

[godlessdustin]

A maverick 88 with a 18.5" barrel will do you just fine for under $300.

[Flyboy]

I think a pump is the best bet; everyone knows the telltale sound of a shotshell being racked.
I bought my Mossberg 500 for about $280 or so at Gander Mountain.
Since a home is generally close quarters, I personally would recommend a collapsable or folding stock if possible and as short a barrel you can legally get. If it ever comes to having to swing around in a hurry, you don't wanna be catching it on anything.
But that's just my opinion.

[556]

Like to keep it under $300 if possible.

-Pump or Semi-auto?

What else should I want on a home defense weapon?

this is easy...

http://www.budsgunshop.com/catalog/product_info.php/cPath/37_871/products_id/42605

or

http://www.budsgunshop.com/catalog/product_info.php/cPath/37_871/products_id/42628

[CamoDeafie]

used Remington 870s and Mossberg 500/Maverick 88s regularly run for $150-250 depending on condition, there are also Winchester model 12s that I have seen for $199 or so; and then the gamut of older Stevens/ High Standard/ Sears/ JC Higgins/ Western Field and so on for below $300..for brand new though, hard to beat the buds gun shop links.

EDIT: let me clarify; these are for the trap/hunting guns with the long barrels; it seems the shorter barreled versions for home defense are always more expensive by at least $100 lol; whereas one could get a new 18.5" barrel for the Mossberg 500 series from Wholesale Sports for $80 and odd change....

[wyrmzr]

For ease of maintenance/reliability, the 870 and Mossy 500 both are very good. Also very easy to get add-ons for, like different barrels, stocks, mag extensions, etc.

[showpare]

The Maverick is one of the best deals going.

[Slimshady]

For home defense you want a short bbl pump shotgun, preferably one they currently make. While older used pump guns can be had for great deals, many have been out of production for years and finding parts if you need them may be a problem. Spare bbls are also an issue, if you ever get into hunting with your shotgun, a spare long bbl is usually cheaper than another shotgun. Everyone and his brother stocks spare Mossberg and Remington bbls, in any configuration you could want. Mag capacity varies, standard is usually 5 rounds. Remington 870s can be easily increased with the addition of a $20 extension tube, Mossberg 500s and Mavericks need to be bought with the extra capacity factory installed as the bbl mounts to the end of the tube and must match.

Buying used is usually the best deal, check for function and fire it first, if possible. Even long bbl hunting guns can be modified for HD use, simply cut the bbl down to a more manageable length. To keep it legal, make sure the bbl is at least 18" long (always best to add at least a 1/2" or so to ensure no mistakes) and 26" overall length from buttplate to muzzle.

For versatility, I like the older 870s, preferably in the "express" line. Black parkerized finish and cheap wood, they customize cheap and don't rust. Many came with a long birdshot bbl and a short slug bbl. Later production they seem to have cheapened them even more, and added dimples in the magazine cap threads to prevent the use of extended mag tubes. Simple matter to drill out the dimples, they are hidden when assembled.

12 guage is going to give you the biggest payload of projectiles, but if your wife or kids may be called upon to use it, 20 guage is also a viable defense round and softens the recoil considerably.

[Delmar]

this is easy...

http://www.budsgunshop.com/catalog/product_info.php/cPath/37_871/products_id/42605

or

http://www.budsgunshop.com/catalog/product_info.php/cPath/37_871/products_id/42628

Choice #2

8 rounds of 12ga baby!

[AE86FL]

Like the previous inputs, the Maverick 88 with either 18.5" 5+1 or 20" 7+1 are your best option IMHO.
If you want a GRS on the SG, the IAC Hawk 982 (870 clone) 18.5" 5+1 will give you the best value. I was able to add a mag tube extension to get it to 7+1.
For ~$200, they are all good pump SG for HD.