I am plaining to install some fluorescent fixtures in my new home for everyday lighting. However, most the lamps I found in Lowe's/Home Depot are the new low-lm/W high CRI type of lamps which I am totally unfamiliar. I was also surprised that the 4-ft F40T12 lamps I bought from Lowes has no shields around the filament (an indication of low quality lamp to me). Can anyone here recommends lamps that are still readily alible & are decent in quality (I like triphosphorus lamp in my home country but seems no longer sold in US?)? Thanks!

Triphosphor F40T12 tubes with a CRI below 87 were banned in July 2012.

Sad to hear Triphosphor T12s extinction. I guess my question would be: Are there any T8/T12 bulb worth buying nowadays in your opinion then?

Cathode guards were never common on American fluorescent lamps except for Philips, and these days many of the Philips lamps only have a shield on one end.  The GE "CX" series 2,900 lumen F40T12s aren't bad assuming they get a decent mercury dose.  They're probably the brightest T12 you'll find at retail.  You could special order 3,600 lumen T10s if you really want bright lamps that'll operate in a T12 fitting. 

Unless you have some vintage T12 fixtures, T8 would make more sense for a new installation.  There are a number of options at or around 3,000 lumens.  Try to avoid the value lamps that are down closer to 2,000.  T5 and T5 HO could get you decent output as well.

Note many of the lamps are triphoshphor, even the T12s, but if they're making use of the CRI loophole the lumens tend to be lower considering the efficiency drops when attaining a CRI of 87+.  The T5s and T8s in addition to being more efficient to begin with often meet the standards without exploiting the CRI exception.  There are some halophosphate lamps as well, mostly in T12 though occasionally in T8 such as Cool White Deluxe or GE's "C" lamps (e.g., C 41) which are basically deluxe halophosphate.

On a side note, I don't know what kind of lamps you're used to, but if you'd like to operate European-spec lamps you could order 36W T8s (several American suppliers stock including lightbubls.com stock them) and operate them on T12 electronic ballasts, or better yet, single-lamp T12 preheat ballasts (which would need to be used/old stock).  Technically the ballasts wouldn't be rated for them, but they should work correctly on electronic and one-lamp preheat.  They won't start up on most rapid start or two-lamp preheat ballasts.

Some rare exceptions for operating F36T8 tubes on 2 lamp F40T12 preheat ballasts are mainly the 1940s and 1950s brick ballasts that are often found in old shoplights and a few art deco fluorescent fixtures like halfpipers and some early louvered fixtures, Such ballasts have been known to operate a pair of F36T8 fluorescent tubes with minimal issues. Like Patrick said, most of the smaller case 2 lamp F40T12 preheat ballasts are only able to keep one F36T8 tube lit while the other F36T8 tube has problems maintaining a steady arc due to the fact that the smaller case 2 lamp F40T12 preheat ballasts have a lower OCV compared to the 1940s and 1950s brick 2 lamp ballasts. I am not entirely sure whether or not F36T8 tubes would have issues on 1940s and 1950s long john 2 lamp F40T12 preheat ballasts.

Thanks Patrick and WorldwideHIDCollectorUSA for the very helpful info.

Interesting to know cathode shields are't common here in the US. Is these because the lamp is usually start with Rapid Start but not choke so less blacken end issue?

The lamp I am nostalgic to was the from a Taiwanese local manufacturer, FL40D-EX/38 (red-golden endcap) which is a direct replicate of Mitsubishi Tri-phosphor lamp from Japan. The lamp was initially in T10 form but reduced to T9 diameter late on. It is not no longer in production.
https://www.ruten.com.tw/item/show?21103106521563

I did found some T10's online (Ushio 3000282 - F40T10/950) which looks really greats on the spec. I feel this could be quite close or way better than my old lamp. However, the price reminds me the Hitachi/NEC lamps my did used to put in my room. Those are the best in brightness/light quality but impossible to find now. They were also T10's as far as I can remember.

Your comments on the ballast is very accurate. Before covid I brought several GE T12 ballasts back to Taiwan and put those in the 4-ft fixtures in my home. FL40D-EX/38 with light-up on both Rapid start electronic (GE240-RS120) and programmed rapid start (GE240PS-MV-N). While the Philips F36T8 TL-D won't start on T12 rapid start but will fire-up on programmed start ballast. The common ballast in Taiwan is the preheat (choke) ballast with step-up transformer (110V line voltage). The preheat ballast can start both Philips F36T8 or T9/T10 lamps without problem. I am not sure how similar Taiwanese preheat ballast to American vintage preheat ballast as I never own one (you can still buy preheat magnetic ballast for 4-ft lamp in Taiwan but I guess this is not the case in US?).

The Taiwanese preheat ballast looks like this. I think it will start American F40T12 with no issues.
https://www.ruten.com.tw/item/show?22138260891316
https://www.ruten.com.tw/item/show?21620737704223

Actually, all F40T12 fluorescent tubes, F36T8 fluorescent tubes, and F40T10 fluorescent tubes in the world are universally interchangeable with each other on single lamp preheat ballasts all over the world. I would love to import some Taiwanese 110v 60hz fluorescent and HID ballasts to run on North American 120v 60hz mains sometime. I have checked out ruten.com.tw before and thought they had some interesting stuff like Osram HQL 100w mercury vapor lamps that seem to be a Taiwanese exclusive from what I am aware of.