Sanctum = Boring
Shad'O & Anomally 2 = Too difficult
Toy Soldiers - Apparently is not finished and I have to pay again for the REAL game once it goes off Early Access.

I've liked:
Kingdom Rush
Go Home Dinosaurs

Plants vs Zombies
Defense Grid
Defender's Quest (GOG)
Cursed Treasures 2 (a flash game similar to Kingdom Rush)

All these are very good tower defense games.

Best tower defense game I've played in a very, very long while. I highly recommend it.

Defender's Quest and Defense Grid are probably the two best tower defense games out there (both have a 2nd game in the works as well..)

Orcs Must Die is a fun series.

You might check out Anomaly here, on GOG :-)

Defender's Quest seems like a solid implementation of the genre. I do like the RPG elements. The character art is charming and the writing is great. I only played the demo that was here on gog though so I only have a little experience with it.

Orcs Must Die 1 and 2 are good games.

Why you no love Sanctum? Sanctum 1 is nice isn't it?

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Thanks for the recommendations.

As for Sanctum there's something about those 3D third person TD's that just feels slow - Whether is extensively long levels or marginally affective traps resulting in each level turning into a lame Wave Brawler or the necessity to play co-op or suffer the same three levels over and over again until you've farmed your character's levels into a tank.

I actually prefer Plants vs. Zombies over Defense Grid (and the rest).

Where is it stated that you need to buy it again? That's generally not how early access works. The idea is to buy at a time you can help by giving feedback, either paying less or more for that opportunity, then keeping the product once it's released properly. I have yet to hear of an early access game where you need to repurchase it*.

* With the sole possible exception being Original Sin beta access keys -- but those were given to backers for free to give to others and may or may not result in owners of such keys needing to buy the game after release (not entirely sure if it's been 100% decided on yet).

As for games to play, Prime World Defenders is one of the better TD games I've played.

I enjoyed playing Toy Defense. It is rather simple and maybe borders on shovelware, but it still entertained me for hours.

Defence Grid, it''s the staple tower defense and one of the best.

Orcs Must Die series. Absolutely love this series. It's a different type of tower defence though, third person where you run around placing traps to fend of hordes of Orcs (I guess almost like Sanctum but not as mindnumbingly boring). Wonderful to play with to get flashy combo trap kills, also love the Warmage :3

Defender quest is a great game but like almost all tower defense games the difficulty escalates in a very unfair way, in the last levels it's almost impossible to beat it.
Or I just suck on tower defense games but I always get very far and got stuck in the last levels, it's even hard using cheats (yeah I use cheat engine to beat it and it was a chore even with unlimited resources )

If you enjoyed Kingdom Rush, there is a sequel called Kingdom Rush:Frontiers which is quite nice, but a bit harder than the first one.
Sanctum also has a pure TD game (not TD/FPS) which is also fun.

I also recommend Defender quest and Defense Grid.

Have to put in a good word for PixelJunk Monsters. I haven't played the PC version but spent a lot of time with it on PSP. And now it's available on GOG!