Hey fellas,
I've got a S&W M&P Sport (1 in 8 twist, 16" barrel), which tells you right off that I'm relatively new to AR-15's, and I'm on a pretty tight budget.

I've been shooting some 3gun with my iron sights, but I think that a decent optic could significantly improve my times, and especially my accuracy at the longer ranges. I'd also like an optic that functions at least passably well in low light conditions, and which could serve in a home defense type of role if called up thusly.

Bottom line: I'd like to able to engage from about 15 yards on out to as much as 200 yards or possibly further. If money were no object, I'd be all over the new Leupold 1.1-8x, but that thing is waaaay out of my price range. I'd like to get an affordable (~<$250) optic that is 1-4x, 1.5-4.5x, or possibly 2-8x at most.

Here are a few that I have been considering:

Bushnell Banner 1-4x (~$85)
http://www.opticsplanet.net/bush-rs-bnr-711432.html

Bushnell Banner 1.5-4.5X (~$75)
http://www.opticsplanet.net/bush-rs-bnr-711545.html

Weaver 1-3x (~$160)
http://www.opticsplanet.net/weaver-rifle-scopes-v3-hunting-849400.html

Millett DMS 1-4x (~$210)
http://www.opticsplanet.net/millett-1-4-x-24-dms-multi-coat-rifle-scope-bk81002.html

Leupold 1.5-4x ($280) –– Both this and the Nikon are more than I can really spend, unfortunately
http://www.opticsplanet.net/leupold-1-4x20-mark-ar-duplex-riflescope-67170.html

Nikon 1-4x (~$290)
http://www.opticsplanet.net/nikon-1-4x20-matte-point-blank-riflescope.html

A lot of people seem to go for the Weaver V3, but I feel like the extra 4x might be worth it on the other optics. The Bushnell Banner scopes seem to get surprisingly good reviews, and anyway this is kind of an interim optic for a few years until I can afford something uber nice, so I don't fancy dropping any more money than absolutely necessary. That said, if the Nikon or the Leupold are 3 or 4 times as good as the Bushnell, I'd think about it.

So anyway, which of those would you choose and why, or is there a different scope that would suit my needs better? I'm extremely budget conscious like I said, so the difference between $100 and $250 is huuuuge to me.

Thanks!

Take a look at the Redfield Revolution. They offer them in 3x9 and 2-7 ( i think) .  Gander Mt has them for $200ish on their site but they were cheaper in the store.

Hmmm, yeah that looks like another solid option.

Redfield Revolution 2-7x for ~$160
http://www.opticsplanet.net/redfield-revolution-2-7x33mm-riflescope-matte-finish-4-plex-accu-range-reticle.html

Now I have more things to decide between, haha.

The Primary Arms 1-4 scope is pretty awesome. I have it on my PSA AR-15 and its only 120$
Primary Arms 1-4x24 Scope

Redfield is owned by Leupold which is a bonus as well.

I m torn between the redfield and the new Nikon p223, which is $149 with free mounts.

i just got a burris fullfield 2 2-7 35mm for 144..if you want a 1-4 then i say go with th nikon

Just got the bushnel banner 1.5-4.5 from optic planet. nice scope. Good service. shipping free.

Yeah, I'm increasingly leaning towards the bushnell banner, probably 1-4x. I'll probably order it in the next day or two unless anyone really thinks it's a bad idea.

If you're wanting to shoot both eyes open, the dot on the Nikon may be your best bet. I haven't heard if they're any good but it comes with a free mount which will save you some money too.

Actually I'm right handed but left eye dominant, so I close mg left eye to shoot. I don't think I could shoot with both eyes open without holding the gun andor my head weird.

You should be able to use an RDS with no magnification.  I am also cross eye dominant.  I can use a non-magnified red dot sight with both eyes open, no problem.  I've tried a Trijicon variable, and the point of aim shift grows as the magnification increases.  I can use it at 1x with both eyes open, but once I turn the magnification up I have to close my left eye.

Back to your original question:  I'd go with the Weaver or one not on your list- Leupold VX Hog:  http://www.midwayusa.com/product/330994/leupold-vx-hog-rifle-scope-1-4x-20mm-pig-plex-reticle-matte

The pig plex actually seems to be damn near what I'm looking for. Leupold. 1-4x. Affordable ($220ish). Illuminated reticle, and it even has BDC holdover points. The only problem is the holdover points are for 30-06.  

If the reticle didn't say "pig plex" on it and have 30-06 holdover points, I'd buy it in a heartbeat. As it is I'll have to think about it.

For the record, I decided to go big or go home. I just ordered the Burris MTAC 1-4x ($400) and a Burris PEPR mount for it ($75). So much for going the cheap route ($475 ain't cheap to me). Hopefully this scope will last me forever. Can't wait for it to get here!

I will need to remove my front sight, yes? Any links on how to do that?