Which telephoto lens to get?

I am in need of some recommendation.
I realized I need some sort of IS for my telephoto lens as hand held shots I took with both 70-200mm f4 L non-is and 200mm f2.8 L were mediocre... So I considered below lenses,

Canon 70-200 f4 L IS
Canon 70-200 f2.8 L IS MK I
Sigma 50-150 f2.8 OS
Sigma 70-200 f2.8 OS
Sigma 150 f2.8 OS

I am okay with any of the above focal lengths so it's more about IQ & overall quality, ooh and "bang for the buck" factor as well.

Just my humble opinion, but the Canon 70-200 f4 IS is one the best zoom lenses Canon ever made. I also recently purchased the Sigma 70-200 2.8 OS from a member here. It is close to the Canon f4, a lot heavier and bulkier, but is doing the job very well in situations were I need the 2.8 vs the 4.0. If I absolutely could only own one, it would be the Canon f4.

I would say go for the 70-200 f4 L IS, one of the sharpest lens Canon has, plus add in light weight and size, I think the choice is easy

One more vote for the F4 IS. I'm hoping to replace my F4 non-IS with this one in the not-so-distant future.

I would go Canon 70-200 f2.8 IS if your budget doesn't allow the mkII.

A f2.8 lens can always be stop down to f4 and not vice versa. Always get the fastest lens that you can afford.

If you don't feel you will really ever need the 2.8 then I'd get the 70-200 f4 IS. That said if I were looking for a lens in that focal range and the 2.8 IS/OS lenses were within my budget, I would be picking up one of those. The Canon 70-200 MkI and Sigma 70-200 are going to be very very close in terms of quality.

If you can find a 70-200 f4 IS for under or around $900, go for it (its overpriced otherwise IMO). Alternatively I would also recommend the Sigma 70-200 2.8 OS if you need 2.8 and don't mind the weight (which I do).

Go for the Canon 70-200 f4 L IS, I owned that lens, and its a superb one.
The only really better lens you can get, is the 2.8 IS L II, for double the Money.

I would recommend either the 70-200 f4 IS, or a lens that isn't on your list: the 70-300L. In both cases IQ is stellar and the lenses are fairly small and compact (the 70-300 is a bit bigger). The extra reach of the 70-300 is very useful. I have and love the f4 IS, and can't quite bring myself to sell it; if I could, I'd buy the 70-300 in a heartbeat. If I were starting from scratch today, I'd definitely choose the 70-300.

Another vote for the F4L IS. Superb optics, lightweight, extremely sharp. WIN!

I have the Sigma 70-200 f/2.8 OS HSM. I like it, but you pay for that f/2.8 with a relatively large, heavy lens. It is bigger than my 100-400L, by a bit. I have seen several reviews that rate the Tamron 70-200 f/2.8 VC as sharper and faster to focus. That puts the Tamron in the league with the EF II.

I use both the Canon 70-200s that the OP mentions and either would be a good choice, depending upon your needs. They are real workhorses.... top quality, durable, reliable.

The f2.8 lens is nice to have when you gotta have f2.8, is completely usable wide open, tho I tend to stop it down a bit for even better image quality when possible. This is probably my single, most-used lens and I've been using it for over ten years.

Recently I added the 70-200/4 IS as a backup and a lighter weight alternative. Its still not a small lens, but probably 25-30% smaller and lighter than the f2.8. I'd let that be your deciding factor... how heavy a lens do you want to carry. This will probably be one of those lenses you'll want handy most of the time, so figure on it being in your camera bag, if not on your camera.

The f2.8 lens comes with the tripod mount. The f4 is sold without it, but one is available at extra cost. The Canon tripod mounts are fairly expensive, but there are third party available for a lot less money. Mine has a Canon t-pod mount on it... don't know how that compares for fit or quality, with the 3rd party.

The f2.8 lens uses and comes with an effective, "tulip-chaped" lens hood. The f4 lens also comes with a lens hood, tho it isn't "tulip-shaped" (I've seen that type offered by 3rd party manufacturers, if preferred).

The f2.8 lens uses 77mm filters. The f4 lens uses 67mm.

Eventually I'll add or upgrade to the 70-200/2.8 IS II, but I'm not in a rush to do so. The original f2.8 IS is pretty darned good.

Haven't tried the third party lenses.

have the 70-200 non is canon which is a great lens and the is version is a little better, get the 2.8 version if you need the 2.8 aperture; that said i tried a 70-300 l on my 1d3 and it has better is than any of the canons except the mkII versions of their lenses

excellent pics from the test too with the 70-300

Thanks for the opinions guys. I narrowed down my choice to f2.8 IS & f4 IS now I just got to try both lenses to feel the size & weight difference.

I believe the size/weight differenence is substansial. But I have the f2.8 V1, and think it's plenty sharp and versatile.