[mickthepope]

I have an SME 3009 on my Thorens TD125 and need some recommendations for a cartridge that would go well with this arm. Would the Denon DL103 be an appropriate match? How much can I spend before I'm wasting money? Any other suggestions or first hand experience with other options would be appreciated. Shure, Nagaoka, ......?

[HAL]

Which series SME3009 do you have?

The Series I and II are good for lower compliance cartridges like MC's.  The Series III is good for high compliance cartridges like the Shure V15 series.

[Mojo Warrior]

Also dependent upon what kind of music that you listen to and your speakers.

[jimdgoulding]

I can just tell you that the Denon 103D cart is a very good choice, IME, and what HAL says.  I used it in a higher mass arm and it was reach-out-and-touch-it pure sounding and dynamic as all get out.  Exciting, it was, viscerally pleasing.  Wish I still had one.

[neobop]

I can just tell you that the Denon 103D cart is a very good choice, IME, and what HAL says.  I used it in a higher mass arm and it was reach-out-and-touch-it pure sounding and dynamic as all get out.  Exciting, it was, viscerally pleasing.  Wish I still had one.

You can often "break the rules" and still get excellent results.  The 103D was the high compliance version of the classic 103, and often used with low mass arms like the Grace 707, SME series III.   Some years ago I bought an old Denon 1250.  It came with a Unitrac (7g) and a 103D. 
neo

[twitch54]

and to add to all of the above, what are you using for a phono pre ? that will make a impact on the range of cartridges.

with regards to the Denon 103 I believe the Zu version of that cartridge takes it to a better level for only a slight $$ increase.