Our new (rented) house has seemingly dozens of recessed halogen spotlights - I presume mains voltage. They are in the kitchen, lounge, dining room, bathroom, shower room and hallways....only the bedrooms have 'normal' fittings.

I know you can now get LED, fluorescent and HID technology. As with everyone, important that light quality is good, and the LED's we have in the kitchen here are pretty poor, but were bought a good few years ago, and technology moves on.

I gave half a cupboard of 'collected from goody bags at eco events'' standard bayonet ones away at Christmas to neighbours....Anyone recommend good spotlight replacements, and a source of them at a reasonable price....

They are GU10 (assumed, I have only had a 15minute look around the place....)
I don't want to replace the fitting, its a brand new house and rented.
Looking for suggestions of good bulbs/types, as I say our old MR16 LED lights are rubbish.

Try replacing 50W halogens with 40W IRC halogen. Only a 20% saving but virtually identical performance in all respects. Going one better would be to use CFL GU10's but I find them very slow to wam up. Otherwise ok. One option is to use a mixture of halogen and CFL (eg halogen over work tops with the rest CFL).

A 50W halogen produces about 900 Lumens of light and the best LEDs I've heard about produce around 500-600 Lumens. They may claim to be as bright as a 50W halogen but in reality they are more like a 35W halogen. You also have to replace the fitting.

..but if anyone knows otherwise do let us know. Easy to get out of date.

Latest LEDs are now puting out 1100 lumens: http://www.leds.de/p439/High_power_LEDs/Osram_Ostar_LEDs/Osram_Ostar_LE_UW_E3B_1120lm.html

However I haven't seen any of those in GU10 fittings yet (and if they were they'd almost cetainly overheat). CFL replacements will be _much_ cheaper than LEDs. LED replacements will be more effcient if you manage to buy bulbs containing latest-generation LEDs, but they tend not to tell you so it's hard to know.

Look for 3x3W Cree or luxeon rebel LEDs or 1 Cree MC-E to get something over 600 lumens. something like this: http://www.leds.de/p250/LED_spots/HighPower_4-Watt_XR-E_LED_Spot_GU10_warm-white_230V.html (which I think will be about 360 lumens). Don;t forget that beam angles vary and matter enormously.

900 lumens from a 50W halogen seems too high to me. I've not heard of halogen over 15 lumens/Watt = 750 lumens. Crappy ones can be 5 L/W=250 lumens. An osram datasheet: http://catalog.myosram.com/zb2b/b2b/start.do?browsername=mozilla%2F5.0%2520%2528x11%253B%2520u%253B%2520linux%2520x86_64%253B%2520en%253B%2520rv%253A1.9.0.7%2529%2520gecko%2F20080528%2520epiphany%2F2.22&browsermajor=5&browserminor=5
states 900cd and 40 degrees beam angle, which is approximately 340 lumens. (7 l/W)

Sorry if that's just confused, rather than illuminated :-)

Thanks a bunch - briefly and exactly what I also needed!

May I recomend that this is moved to the essential for newbies section. I think most of the info is here already (ish) but nothing as sucinct and with so many links; hence, essential/basics....any seconder to my motion?